Designated Historic Civil Engineering Landmarks New!
Alphabetical Listing
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| Project Name, Location | Designated Year |
| Acequias of San Antonio, San Antonio, Texas, USA This is one of the earliest uses of engineered water supply and irrigation systems in the United States. The first of eight original acequias was under construction in 1718 and two are still in operation. The remains of one are visible on the grounds of the Alamo. | 1968 |
| Acquedotto Traiano-Paolo, Rome, Italy The original aqueduct built by the Emperor Trajan, circa 110 AD, was a symbol of the advanced infrastructure of ancient Rome. Largely rebuilt in the 17th Century, it continues to provide water for the fountains of Rome as well as fulfills a partial need of the modern city. | 1992 |
| Acueducto de Segovia, Segovia, Spain One of the best preserved Roman constructions, the Aqueduct at Segovia was still in use as recently as fifty years ago. Constructed around 50 AD during the reign of the Roman Emperor Trajan, out of some 200,000 granite blocks, the aqueduct was made without concrete. | 1999 |
| Alaska Highway, Canada/United States The Alaska Highway, extending from Dawson Creek, British Columbia, to Delta Junction, Alaska, was built in 1942 in just eight months. This 2500-km highway provided an essential transportation link for troops and equipment to Alaska and Northwest Canada during World War II. | 1995 |
| Allegheny Portage Railroad, Hollidaysburg, Pennsylvania, USA * ‡ Opened in 1834, this railroad was designed to carry fully-loaded canal boats over the Allegheny Mountains (summit of railroad at 2,291 feet above sea level). The thirty-six mile project included the first railroad tunnel in the United States, ten double-track inclined planes and four viaducts. In 1844, John A. Roebling replaced the hemp rope with wire rope, the first such use in the United States. | 1987 |
| Alvord Lake Bridge, San Francisco, California, USA * ‡ Built in 1889 by Ernest L. Ransome, this bridge, located in San Francisco's Golden Gate Park, is the oldest (and first to be constructed in the United States) concrete arch bridge with steel reinforcing bars. | 1969 |
| Armour-Swift-Burlington Bridge, Kansas City, Missouri, USA This unique, telescoping vertical-lift, steel-truss bridge spanning the Missouri River at Kansas City since 1912 is representative of the innovative moveable bridges designed by former ASCE President, and leading bridge engineer, John Alexander Low Waddell. It was originally designed with a movable lower span to carry the rail traffic while the upper span carried uninterrupted highway traffic. Recent renovation has removed the highway traffic. | 1996 |
| Arroyo Seco Parkway, Los Angeles, California, USA This 6.7-mile parkway was the first freeway to be built as a state highway in the United States and is the first freeway west of the Mississippi. | 1999 |
| Ascutney Mill Dam, Windsor, Vermont, USA Built in 1834 and still in service today, this is among the very earliest masonry dams of significant size. Made of granite and measuring 120 feet in length with a crest 42 feet above tailwater, it is the structural precursor of today's concrete gravity dams. | 1970 |
| Atlantic City Convention Hall, Atlantic City, New Jersey, USA * When completed in 1929, this hall was the world's largest auditorium and the greatest permanent span three-hinged roof arch system ever built. Now known as Boardwalk Hall, this bold feat of structural engineering remains in service today. | 1983 |
| Bailey Island Bridge, Harpswell, Maine, USA * Completed in 1928, the Bailey Island Bridge traverses an 1,150-foot stretch of high tidal water with swift currents, severe saltwater exposure, and heavy winter ice floes. This challenge was met with an innovative split-stone open crib construction, carrying the concrete deck; a concrete span crosses the navigation channel. The bridge continues to serve its function without impeding tidal flow; an exceptional example of an engineering solution to meet extremely unusual conditions. | 1983 |
| Baltimore & Ohio Roundhouse & Shop Complex, Martinsburg, West Virginia, USA This structure is the sole surviving cast-iron framed roundhouse and an important example of mid-19th century industrial building design. Designed by Albert Fink, in collaboration with Benjamin H. Latrobe, it represents an early use of standardized, prefabricated iron structural elements to create an efficient and fire-resistant building. | 2001 |
| Bayonne Bridge, New Jersey/New York State, USA * Completed in 1931, this steel arch bridge, designed principally by Othmar Ammann (Hon.M.ASCE), was the greatest span (1,675 feet) of its type in the world and remained so until the New River Gorge Bridge at West Virginia exceeded it by twenty-five feet in 1977. The Bayonne, which connects Bayonne, N.J. to New York City, N.Y, was the first major bridge to use manganese steel for its main structural members. The construction process employed an innovative system of falsework, developed to preclude the need for heavy anchorages. | 1985 |
| Belle Fourche Dam, Belle Fourche, South Dakota, USA A key element in the Belle Fourche reclamation project, this was the largest homogeneous rolled-earth fill dam in the world when completed in 1911. The project's engineers developed many of the quality standards that became the practice for later major compacted-soil structures. | 1988 |
| Bethlehem Waterworks, Bethlehem, Pennsylvania, USA ‡ The first known pumping system providing drinking and wash water in the North American colonies. The existing building is dated 1761, but it was preceded by an experimental frame building dated 1754. A wooden waterwheel, driven by the flow of Monocacy Creek, drove wooden pumps which lifted the water through wooden pipes to the top of the hill where the water was distributed by gravity. | 1971 |
| Bidwell Bar Suspension Bridge, Oroville, California, USA * An example of the typical suspension bridges constructed during California gold rush days, the Bidwell Bar Suspension Bridge was built in 1856 over the Feather River approximately ten miles northeast of Oroville. The bridge has been reconstructed at a historical park about a mile from its original site and it is the only remaining suspension bridge of its time in the West. | 1967 |
| Blenheim Bridge, North Blenheim, New York, USA ‡ Constructed in 1855, this covered wooden truss bridge, designed and built by Nicholas Powers, is the longest (210 feet) bridge of its kind in the world. This record clear span was achieved by an ingenious interlocking of truss and arch action and remains today as a tribute to American engineering. This bridge is one of the few bridges on the Register of National Historic Landmarks of the National Park System. | 1983 |
| Blimp Hangars, Tustin, California, USA These blimp hangars constructed in 1943 remain the largest clear span wooden structures in the world. They demonstrate civil engineering ingenuity in response to a wartime shortage of typical building materials. | 1993 |
| Blue Ridge Parkway, Shenandoah National Park, Virginia-North Carolina, USA Begun in 1935, this 469-mile scenic highway was, at the time, the longest road ever planned as a single unit in the United States. The parkway includes numerous engineering accomplishments over a wide variety of terrains, and contains the first segmental structure in North America built using progressive placement (Linn Cove Viaduct). The Parkway was designed to provide scenic variety, including road routing along mountainsides, plateaus, streams, and broad river valleys, presenting motorists with one of the most diversified experiences in the world. | 1999 |
| Bollman Truss Bridge, Savage, Maryland, USA * ‡ The noted Baltimore bridge engineer Wendel Bollman built this eighty foot double truss span in 1869. It is the only remaining example of a patented design that was used extensively on the Baltimore & Ohio and other railroads. | 1966 |
| Bonneville Dam, Columbia River System, Bonneville, Oregon, USA ‡ This structure, put on stream in 1937, was the first Federal dam of fifty-five major hydroelectric projects on the Columbia River. They constitute the largest hydroelectric system in the world and have contributed immeasurably to the development of the Pacific Northwest and the nation. | 1987 |
| Borden Base Line, Hatfield, Massachusetts, USA Completed in 1831, the Borden Base Line of over 39,000 feet remains today an outstanding achievement in precision measurements made possible through the care and inventiveness of the American civil engineer, Simeon Borden. Through this work, American skill in geodetic engineering attained international acclaim. | 1981 |
| Boston Subway, Boston, Massachusetts, USA ‡ Open for service in 1897, this subway was the first in North America and, as an engineering innovation, became the prototype for other urban mass transit subway systems in the United States. | 1978 |
| Bridgeport Covered Bridge, Nevada City, California, USA Built in 1862, this bridge is the longest single span (230 feet) covered bridge west of the Mississippi River. The design is best described as a Burr truss. This bridge, which originally carried heavy freight between Marysville, California and Virginia City, Nevada, remains in service. | 1970 |
| Bridges of Keeseville, Keeseville, New York, USA Keeseville has three remarkable operational 19thcentury bridges of different types all within five hundred yards of each other: a one hundred foot span stone arch (1843); a wrought iron Pratt truss (1878); and a twisted wire cable suspension bridge (1888). The evolution of civil engineering materials, analysis, and design, are clearly illustrated by these structures, all of which remain in service. | 1987 |
| Bridges of Niagara, Niagara Falls, Canada/United States The Niagara River gorge has been the site of a number of historically significant bridges. Charles Ellet, Jr.'s suspension bridge of 1849, John A. Roebling's railroad suspension bridge of 1855, Charles C. Schneider's railroad cantilever of 1883, Leffert L. Buck's two arch bridges (1897-1898), and Shortridge Hardestry's Rainbow (1941) all influenced the development of long-span bridge design and construction. | 1992 |
| Brooklyn Bridge, New York City, New York, USA * ‡ When completed in 1883, the Brooklyn Bridge was the longest suspension bridge in the world. It was the first to use steel cables and trusses. Designed by John A. Roebling, it was built under the supervision of his son Washington. | 1972 |
| Brooks AFB, Old Hangar 9, San Antonio, Texas, USA In 1918, during its first year of operation, Brooks Field consisted of sixteen hangars with extensive support facilities. Of these early buildings, Hangar 9, dedicated to the memory of Edward H. White II, is the only structure still in existence. | 1998 |
| Buffalo Bill Dam, Cody, Wyoming, USA * At the time of its completion in 1910, this dam was the highest in the world and the only one with a height/width ratio greater than one. This was the first major concrete arch dam to be designed and built using the trial-load analysis technique. | 1973 |
| Bunker Hill Covered Bridge, Claremont, North Carolina, USA The Bunker Hill Covered Bridge, constructed in 1895 and restored in 1994, is the only remaining example of the improved lattice truss timber bridge patented by Herman Haupt in 1839. Haupt, who was in charge of railroad engineering for the Union Army during the Civil War, evolved the design while developing a rational method for truss analysis as outlined in his 1851 book, General Theory of Bridge Construction, one of the earliest American books on bridge engineering. | 2001 |
| Cabin John Aqueduct, Cabin John, Maryland, USA * ‡ Built between 1857 and 1863 under the direction of Capt. Montgomery C. Meigs, this was the longest span stone masonry arch in the world until 1903. This structure is still serving the basic purpose for which it was built, providing water to Washington, DC, as well as carrying traffic loads. | 1972 |
| Caledonian Canal, Scotland This 60 mile long 110 ft wide ship canal across Scotland between the north and Irish seas was constructed between 1804 and 1822 using state-of-the-art technology on an unprecedented scale. The civil engineer, Thomas Telford, working with consulting engineer William Jessop and contractors John Simpson, John Wilson and John Cargill, built the canal with 28 locks 170 ft or 180 ft long, 40 ft wide, and 25 ft deep. At the time, it was the largest series of locks ever built. The canal significantly advanced highland development and engineering knowledge. | 2007 |
| Canton Viaduct, Canton, Massachusetts, USA * Since its opening in 1835, the Canton Viaduct has been in continuous service to high speed rail. This 21-arch granite masonry bridge was uniquely designed with hollow spaces between walls, connected by solid buttresses between arches. The slightly curved, functional bridge is 615 feet long, 70 feet high and 22 feet wide. | 1998 |
| Cape Cod Canal, Barnstable, Massachusetts, USA Under Chief Engineer William Barclay Parsons (Hon.M.ASCE), this sea-level canal's seventeen mile length opened in 1914 after being designed to cope with a tidal differential of 4.5 feet coupled with a three-hour out-of-phase tidal cycle without the use of locks. The canal has since been improved and is now maintained by the U.S. Army Corps of Engineers. | 1985 |
| Cape Hatteras Lighthouse, Cape Hatteras, North Carolina, USA Constructed in 1870, this lighthouse, at 198 feet, is the tallest in the United States and the second tallest brick light tower in the world. As part of an integrated system of navigational aids, providing safer maritime travel along the mid-Atlantic coastline, the lighthouse warned mariners of the treacherous "diamond shoals" located just off Cape Hatteras. In 1999 the lighthouse was moved 2500 feet from the shore to protect it from the changing shoreline. | 1999 |
| Carrollton Viaduct, Baltimore, Maryland, USA * ‡ Designed and built by Casper Weaver, the viaduct was the first major structure on an American railroad. Completed in 1829, this two-span masonry arch remains in full service today, a monument to our civil engineering heritage. | 1982 |
| Castillo de San Marcos, St. Augustine, Florida, USA * This is a unique link between medieval European military engineering and modern American civil engineering. It is the oldest (1695) major engineered structure in the United States. | 1975 |
| Cedar Falls Water Supply, Seattle, Washington, USA The forerunner of the public power movement, this was the first municipally owned hydroelectric project in the United Sates. | 2000 |
| Central Pacific Railroad, Sacramento, California, USA * America's first transcontinental railroad began in Sacramento in 1863, and was completed in 1869 at Promontory, Utah. The railroad was organized and located over the Sierra Nevada Mountains by Theodore Judah. | 1968 |
| Chain of Rocks Water Purification Plant, St. Louis, Missouri, USA At this plant, a civil engineer and a chemist cooperated in the spring of 1904 on an innovative process of chemical coagulation (ferrous sulfate/lime) to purify the highly turbid water of the Mississippi River. This pioneering effort was recognized internationally as an outstanding success in the field of municipal water supply. | 1981 |
| Charles River Basin Project, Boston, Massachusetts, USA In 1910, this environmental engineering project converted 675 acres of estuarial muck into a freshwater basin of beauty and recreational value. John R. Freeman (1922 ASCE President) was Chief Engineer for the study committee, and Frederic P. Stearns (1906 ASCE President) was consulting engineer for the construction. This project has served as an international model in environmental engineering, landscape architecture, and urban planning. | 1981 |
| Charleston - Hamburg Railroad, Charleston, South Carolina, USA At the time of its construction in 1833, the Charleston-Hamburg Railroad was the world's longest railroad (136 miles). Designed and constructed by Horatio Allen (1873 ASCE President), it was the first to operate passenger trains on an established schedule, the first to use a steam locomotive built in the United States, the first railroad to be completely locomotive powered, and the first to carry mail. | 1969 |
| Charlestown Naval Dry Dock, Boston, Massachusetts, USA * ‡ Built between 1827 and 1833 the Charlestown Naval Dry Dock, Boston, Massachusetts and the Gosport Naval Dry Dock, Norfolk, Virginia are two of the earliest major structures of their type in the United States. Despite the lack of scientific knowledge of hydraulics and geotechnology at the time, Loammi Baldwin II and his associated engineers successfully completed these projects which served the U.S. Navy for well over a century. | 1977 |
| Cheesman Dam, Denver, Colorado, USA When completed in 1905, the Cheesman Dam was the world's highest gravity stone arch masonry dam. It was the first major dam in the United States to incorporate the gravity arch concept in its design. As the key structure in the Denver water supply system, the dam provided the first continual on-stream storage of water for municipal use in the semi-arid west. | 1973 |
| Chesapeake and Delaware Canal, New Castle, Delaware, USA The Chesapeake and Delaware Canal was originally built between 1825 and 1829 by the Erie Canal civil engineering team of Benjamin Wright ("Father of American Civil Engineering"), Canvas White, and Nathan Roberts. Benjamin H. Latrobe, Sr., had begun the project a few years earlier. While only 14 miles long, this canal was one of the most expensive canals ever built in America. The main reason was the 3-mile long, 90-foot deep cut, ingeniously engineered and constructed, that had to overcome terrain composed of unstable earth and tidal marshes. Between 1921 and 1927, the United States Army Corps of Engineers converted the project into a sea-level canal, eliminating its locks, and expanding its width and depth. The canal remains in service today as a major national waterway and a tribute to Albert Gallatin's original "master transportation plan" of 1808. | 1985 |
| Chesbroughs Water Supply System, Chicago, Illinois, USA This famous 1869 water tower and pumping station in Chicago stand as symbols of civil engineering achievement. A two-mile tunnel under Lake Michigan carried water from a timber intake crib to the pumping station in order to provide a safe potable water supply for the citizens of Chicago. The tunnel was designed to supply fifty gallons of water per capita per day for one million inhabitants. The chief engineer was Ellis Chesbrough (1878 ASCE President). | 1972 |
| Choate Bridge, Ipswich, Massachusetts, USA * ‡ The Choate Bridge of Essex County, completed in 1764, is the oldest documented two-span masonry arch bridge in the United States. It presents a unique example of two co-existent forms of 18th century masonry arch construction in one bridge. | 2008 |
| City Plan of Philadelphia, Philadelphia, Pennsylvania, USA Dating from 1682, the City Plan of Philadelphia has provided a model which has helped mold the development of cities throughout the country. Key features, many of which were firsts in the United States, include a gridiron street pattern, street widths appropriate to their function, open public squares, a central public square for future public building, and the provision of ample land for future development within the plan. | 1996 |
| City Plan of Savannah, Savannah, Georgia, USA ‡ The Savannah city plan, whose execution began in 1733, is the oldest city plan in the United States to use a repetitive modular grid with mixed residential blocks and multi-purpose public areas. This model has produced a city internationally known for the beauty of its neighborhood squares. It is a most notable example of an urban planning concept still emulated by modern civil engineers-planners. | 1977 |
| Cleveland Hopkins Airport, Cleveland, Ohio, USA Completed in 1925, this Ohio airport is the first major municipal airport to provide an integrated engineered system of paved landing surfaces, floodlit runways, and a terminal complex consisting of both operational buildings and hangars. | 1979 |
| Colorado River Aqueduct, Blythe, California, USA * The 242-miles Colorado River Aqueduct made the large scale population and economic growth of Southern California possible. Constructed between 1933 and 1941, this aqueduct was selected in 1955 as one of ASCE's original "Seven Modern Civil Engineering Wonders" because of its unprecedented cost, length, pumping rate, and lift as well as its construction under conditions of severe climate and difficult terrain. | 1994 |
| Columbia River Scenic Highway, Portland, Oregon, USA * ‡ Built between 1913 and 1922, this is an outstanding example of civil engineering. It blended seventy-four miles of roadways, tunnels, viaducts, and overlooks harmoniously into the natural environment. Opened early in the automobile era, this highway was responsible for accelerating the development of the Northwest, while preserving its beauty. | 1984 |
| Columbia-Wrightsville Bridge, Columbia, Pennsylvania, USA When completed in 1930, this was the longest (one-mile) multiple-arch concrete highway bridge in the world. To achieve this economically, civil engineers developed a unique system of combining a parallel construction railway, track mounted whirly cranes and re-usable steel forms. It remains in full service today and is also the site of a historic American Covered Bridge that existed between 1812 and 1833. | 1984 |
| Conwy Suspension Bridge, Conwy, Wales A major structure on the strategically important Bangor-to-Chester road, Conwy Suspension Bridge, Telford's most dramatic creation in the gothic style, was built with the identical technology developed for the larger Menai Bridge and still has its original iron chains. | 2002 |
| Conwy Tubular Bridge, Conwy, Wales Built for the Chester-Holyhead Railway, which provided rail access to the sea crossing to Ireland, this bridge was a forerunner to Robert Stephenson's Britannia Bridge over the Menai Strait. Conwy Tubular Bridge was the first railway bridge in which trains ran through the main girders. It represents a pioneering use of wrought iron for bridges and a major advance in the development of box-section girder elements. | 2002 |
| Cornish - Windsor Covered Bridge, Windsor, Vermont, USA * This two-span covered bridge, with an overall length of 460 feet, is the longest covered bridge existing in the United States. It is a Town lattice timber truss design, a type widely used on many early timber bridges and later in building construction. Rebuilt in 1988, the bridge was originally constructed in 1866. | 1970 |
| Cortland Street Drawbridge, Chicago, Illinois, USA Completed in 1902 and still in use, this trunnion-bascule highway bridge was the first of its kind and became the model for this type of urban transportation structure. | 1981 |
| Craigellachie Bridge, Moray, Scotland This elegant 150 ft span cast iron arch was erected in August-September 1814. It is the earliest surviving example of a new portable lattice-braced standard type developed for use at wide sites unsuitable for masonry spans. Thomas Telford was the designer and engineer for this new type of arch. At least 10 arches were erected in Britain from 1812-30. | 2007 |
| Cranetown Triangulation Site, Cedar Grove, New Jersey, USA Fieldwork begun in 1816 established this triangulation point in 1817 as an essential part of the first precise geodetic survey in the United States. The present Coast and Geodetic Survey, at the request of the History and Heritage Committee, relocated this point, which is a monument to Ferdinand Hassler and other skilled early American civil engineer surveyors. | 1986 |
| Croton Water Supply System, New York City, New York, USA * ‡ Completed in 1842 by Chief Engineer John B. Jervis (Hon. M. ASCE), this system was the most outstanding municipal water supply system in the United States and the prototype for many large scale projects that followed. Its forty mile masonry aqueduct, including High Bridge in New York City (still standing), was unprecedented. | 1975 |
| Crozet's Blue Ridge Tunnel, Waynesboro, Virginia, USA * This 4,270-foot tunnel, completed in 1858, represents the culmination of civil engineering technology based on manual drilling methods. Designed and built by Claude Crozet, it was the longest railroad tunnel in the United States at the time. Through its linkage with the Ohio River basin and Southern ports, it has greatly facilitated the development of ocean-borne commerce in the South. | 1976 |
| Cumbres and Toltec Scenic Railway, Chama, New Mexico, USA ‡ This railroad, constructed between 1879 and 1880, is a conjunctive part of the Denver & Rio Grande Western Railroad. It is sixty-four miles in length and is now one of the last narrow gauge railroads. | 1976 |
| Davis Island Lock and Dam, Pittsburgh, Pennsylvania, USA When constructed between 1878 and 1885, this lock facility, the world's first rolling lock gate and the widest lock chamber ever built, represented a full-scale civil engineering experiment of unprecedented size and scope. In use until 1922, it served as the prototype for fifty similar locks in the Ohio River canalization. It was also the largest movable dam built in the 19th century. | 1985 |
| Delaware Aqueduct of the Delaware & Hudson Canal, Lackawaxen/Minisink Ford, Pennsylvania/New York State, USA * ‡ This span is John A. Roebling's earliest, still-standing suspension bridge and perhaps the oldest existing cable suspension bridge in the world (that retains its original principal elements). This bridge is considered one of the nation's most significant engineering relics and the earliest work of Roebling. It was completed in 1848 as an aqueduct bridge to carry the Delaware & Hudson Canal across the Delaware River. It was completely restored by the National Park Service in 1983. It goes from Lackawaxen, PA to Minisink Ford, N.Y. | 1972 |
| Denison Dam, Denison, Texas, USA This was the largest rolled-earth fill dam in the United States when it was constructed from 1939 to 1943. The civil engineering design and rolled-earth construction techniques implemented in this project were subsequently applied to US Army Corps of Engineers multiple purpose lake projects that provided flood control, water supply, electric power, recreational and wildlife benefits on the prairie lands of the American West. | 1993 |
| Detroit-Windsor Tunnel, Detroit, Michigan, USA When constructed from 1928 to 1930, this subaqueous single tube highway tunnel between Michigan and Ontario, Canada, was an exceptional engineering achievement using three distinct tunneling techniques (cut and cover for the land sections, compressed air shield for the channel approaches and trench and sunken tube under the main channel). Of particular note is that the thirty-two foot diameter main channel section involved sixty-five miles of arc welding, the first major use of arc welding in tunneling history. The helical ramps at the Detroit approach were another engineering innovation. | 1982 |
| Dismal Swamp Canal, Chesapeake, Virginia, USA * This canal is the oldest surviving artificial waterway in continuous use in the United States. Construction began in 1793 and the canal, utilizing a system of seven locks, was opened in 1805. Initially dug by hand, this canal still serves as a scenic route along the Intracoastal Waterway. | 1987 |
| Dorton Arena, Raleigh, North Carolina, USA The arena represents the first permanent use of a cable-supported roof system in the world. Among those who contributed to the realization of Matthew Nowicki's (1910-1950) original concept were architect William Deitrick (1895-1974), structural engineer Fred Severud, P.E., (Fellow ASCE) (1899-1990), and contractor William Muirhead Construction. Owned by the State of North Carolina Department of Agriculture and Consumer Services, the arena is named after fair manager J.S. Dorton. | 2002 |
| Druid Lake Dam, Baltimore, Maryland, USA When completed, the Druid Lake Dam was the first major earthfill dam to be constructed in the United States. Built between 1864 and 1871, it had a number of unique characteristics. First was the challenge of constructing in a ravine an earth barrier having sufficient height to form a reservoir of sufficient capacity. In addition, there was the challenge of using materials to build an economical dam which would be structurally sound and long lasting. It was the forerunner of other United States earthfill dams. | 1971 |
| Dublin-Belfast Rail Link, Ireland/Northern Ireland The Dublin-Belfast rail-link, constructed between 1842 and 1855, provided, and continues to provide, a link between Northern Ireland and Ireland. It is recognized for the 536m long Boyne Bridge and Viaduct, which represented the first large-scale use of wrought-iron latticed girders and the first full-scale test of continuous beams. | 1996 |
| Duck Creek Aqueduct, Metamora, Indiana, USA Constructed in 1846, this 71-foot span is the oldest covered wooden aqueduct in the country. It still carries the Whitewater River Canal over Duck Creek. The aqueduct was reconstructed in 1948 using much of the original material. | 1992 |
| Dunlap's Creek Bridge, Brownsville, Pennsylvania, USA * Dunlap's Creek Bridge is the oldest all-metal arch bridge in the United States. Conceived by Captain Richard Delafield in 1830, it was completed in 1839, and it emphasized the feasibility of cast iron in bridge construction at that time. | 1978 |
| Durango-Silverton Branch of the D&RGW RR, Durango, Colorado, USA * ‡ Now used for tourist excursions, this is one of the last of the narrow gauge railroads that linked the Colorado mining towns of Durango and Silverton. Constructed in 1882, the railroad is an example of the important role that civil engineering played in developing the west. | 1968 |
| Eads Bridge, St. Louis, Missouri, USA * ‡ Completed in 1874, this celebrated bridge is named for James Buchanan Eads, its designer and builder. To found the mid-river piers on solid rock, Eads used the first large pneumatic caissons in the United States. Their sinking represented the deepest subaqueous construction work in the world at the time. The scale of the structure was unprecedented: the more than five hundred foot span of the center arch exceeded by some two hundred feet any arch built previously. The arch ribs were made of steel, its first extensive use in a bridge. An innovation was the cantilever erection of the arches, without falsework, the first instance of this for a major bridge. | 1971 |
| Eads South Pass Navigation Works, Venice, Louisiana, USA This project enabled the entire Mississippi River basin to have direct deep draught marine access to the oceans of the world. The boldness of its engineer, James B. Eads (1882 ASCE Vice-President), resulted in a monumental work whose success was internationally acclaimed. Completed in 1879, it is today a classic of hydraulic engineering. | 1982 |
| East Maui Irrigation System, East Maui, Hawaii, USA This pioneer irrigation system was constructed between 1876 and 1923 by private enterprise to irrigate sugar cane plantations. It consists of seventy-four miles of tunnels, ditches, inverted siphons, and flumes with a capacity of 455 million gallons per day. | 2002 |
| Ecole Nationale des Ponts et Cheussees, Paris, France Founded by Trudaine in 1747, and still operating, this is the oldest civil engineering school in the world. Its graduates have had a major impact on the art and science of civil engineering worldwide. | 1988 |
| Eddystone Lighthouse, Plymouth, England Erected between 1756 - 1759 on the Eddystone Rocks by John Smeaton, was among the first individuals to call themselves a civil engineer, it was the first masonry-tower lighthouse to be built at sea. Its form was universally adopted. Removed in 1882 because of erosion of its foundation, the lighthouse was partially reconstructed on the Plymouth Hoe in 1884. | 1991 |
| Eiffel Tower, Paris, France When completed in 1889, this world renowned structure was the highest in the world. Eiffel chose to use wrought iron instead of steel because of its easier workability at the time. This is a joint designation with the Societe des Ingenieurs et Scientifiques de France, the successor organization for the France Society of Civil Engineers, which was founded in 1848, and of which Gustave Eiffel was an early president. | 1986 |
| El Camino Real, Santa Fe, New Mexico, USA El Camino Real, the Royal Road, was the 1,500-mile route that connected Santa Fe and the rest of New Mexico with Mexico City during Spanish Colonial times. Begun in 1598 when Don Juan de Onate led a group of settlers along it into New Mexico, it continued to be used until the railroad put it out of business in the 1880s. | 1986 |
| El Camino Real (The Royal Road) Eastern Branch, San Antonio, Texas, USA This major Spanish pioneer transportation artery, begun in the 16th century, provided support, defense, and political stability for early colonists. It extended from the present-day Republic of Mexico through Texas, Louisiana, Mississippi, Alabama, and Florida. | 1986 |
| Elephant Butte Dam, Truth or Consequences, New Mexico, USA This dam, completed in 1916, created the largest reservoir in the world at that time and was the first civil engineering water project associated with the international allocation of water. | 1976 |
| Ellicott's Stone, Mobile, Alabama, USA After the Republic was formed, the government commissioned Andrew Ellicott to establish an international boundary. This "stone", located a few miles north of Mobile, Alabama, is the key extant monument from the historic survey, which located with remarkable accuracy the 31st parallel between the United States and Spanish West Florida in 1799. | 1968 |
| Embudo, New Mexico Stream Gauging Station, Embudo, New Mexico, USA Established in 1889 as the first stream gauging system ever undertaken, this project led to the development of techniques which have been used extensively to collect essential data for water resources projects, land use and urban planning. This station remains in use. | 1973 |
| Erie Canal, Albany, New York, USA * ‡ Begun in Rome, New York in 1817, and completed in 1825, this 365-mile long canal cut a swath through New York State from the Hudson River at Albany to the Great Lakes at Buffalo. Called the first practical school of Civil Engineering in America, it was a principal route for emigrants from the East and agricultural products from the West. In its day, it was the world's longest canal and America's greatest engineering feat. Benjamin Wright, the "Father of American Civil Engineering," was Chief Engineer. | 1967 |
| Fink Deck Truss Bridge, Lynchburg, Virginia, USA A unique survivor of a truss system widely used between 1854 and 1875, this cast and wrought iron truss system was patented by Albert Fink (1880 ASCE President) in 1854. Constructed in approximately 1870 as a railroad bridge, it was converted to vehicular use in 1893. The truss elements were moved to a park in Lynchburg, Virginia in 1985, where it is now used as a footbridge. | 1979 |
| Fink Through Truss Bridge, Hamden, New Jersey, USA * Possibly the oldest metal truss bridge in the nation, this bridge, completed in 1858, was constructed of cast and wrought iron and demonstrated a major breakthrough in patented railroad bridge design and construction. A car collision in 1978 destroyed this bridge. | 1979 |
| First Concrete Pavement, Bellefontaine, Ohio, USA This pavement, laid in 1893 at Bellefontaine, Ohio represents the first engineering use of portland cement concrete street pavement in public road construction. It was the forerunner of many thousands of miles of similarly constructed roads in the United States. | 1976 |
| First New York Subway, New York City, New York, USA * Completed between 1900 and 1904, this project was the first major rapid transit subway system in the United States. Chief Engineer William Barclay Parsons (Hon. M. ASCE) was responsible for many innovative practices in cut-and -cover excavation, underground steel bent construction and subaqueous shield tunneling through rock. (Jointly designated a Mechanical Engineering Landmark by the American Society of Mechanical Engineers.) | 1977 |
| First Owens River - Los Angeles Aqueduct, Bishop, California, USA * This aqueduct system, unprecedented in size and scope at the time of its 1913 completion, was the prototype for the extensive water supply systems needed to support the major urban complexes of today. Begun in 1907, this aqueduct is more than two hundred miles long and provided Los Angeles with a flow of 440 cubic feet per second. | 1971 |
| Firth of Forth Railway Bridge, Queensferry, Scotland Built between 1882 and 1890, this British railway bridge held for twenty-seven years the world's record for span (521 meters). To achieve this, John Fowler and Benjamin Baker (Hon.M. ASCE) developed a unique double cantilever profile and utilized mild steel. This structure remains in service today as a link in the British Rail system. The 101-meter tall towers allow a shipping clearance of forty-six meters. The overall length of the bridge is 2,529 meters. | 1985 |
| Five Stone Arch Bridges, Hillsborough, New Hampshire, USA These five bridges, Carr Bridge (mid 1800's), Gleason Falls Bridges (circa 1830), Gleason Falls Road over Beard's Brook (mid 1800's), Second New Hampshire Turnpike Bridge (circa 1864), and Sawyer Bridge (circa 1866), constitute the largest extant cluster of dry-laid stone arch bridges within the U.S. They were built by trained masonry craftsmen and continue to demonstrate the durability of such construction. | 2002 |
| Folsom Hydroelectric Power System, Folsom, California, USA * ‡ Completed in 1895, the Folsom Hydroelectric Power system was the second system (Mill Creek No. 1, near Redlands, CA was completed two years earlier) providing long distance high voltage three-voltage transmission for significant municipal and industrial multi-purpose power use. | 1975 |
| Forth & Clyde Canal and Union Canal, Glasgow, Scotland These canals, completed in 1790, are recognized as the world's first man-made, sea-to-sea ship canal project. Constructed with no natural waterways included on its route, this project is a monument to the civil engineering profession and was a significant factor in the advancment of the industrial revolution in Scotland. | 2000 |
| Fort Peck Dam, Ft. Peck, Montana, USA * When built between 1933 and 1940 by the U.S. Army Corps of Engineers, Fort Peck Dam, with its crest extending four miles, was over five times larger than the largest dam in the world. For thirty years after its construction, Fort Peck Dam was the largest hydraulic-filled dam in the world. During construction, environmental extremes, problematic soil conditions, and the enormous scale of the project required monitoring of site conditions using the latest geotechnical instrumentation, careful selection of materials and many innovations in construction techniques. | 1990 |
| Frankford Avenue Bridge, Philadelphia, Pennsylvania, USA This three-span stone arch bridge over Philadelphia's Pennypack Creek was built in 1697 and has served as an important roadway ever since. It is the first known stone arch to be built in this country and probably the oldest bridge in the United States. | 1970 |
| Fritz Engineering Laboratory, Bethlehem, Pennsylvania, USA Constructed between 1909 and 1910 by John Fritz (Hon. M. ASCE), the Fritz Engineering Laboratory at Lehigh University was the largest and best-equipped university structural laboratory in the United States at the time. Tests conducted at the lab were instrumental in the development of skyscrapers and other major structures. The lab served as a prototype for subsequent university and research laboratories. | 1991 |
| Galveston Seawall and Grade Raising, Galveston, Texas, USA Following the hurricane of 1900, the greatest natural disaster in U.S. history, with the loss of 6,000 lives, civil engineers designed and built a concrete seawall and raised the elevation of Galveston Island, using pioneering materials and methods. After almost one hundred years and numerous hurricanes, only minimal damage and loss of life have occurred. | 2001 |
| George Washington Bridge, Fort Lee/New York City, New Jersey/New York, USA * The 3,500 foot center span of this world-renowned suspension bridge, completed in 1931, virtually doubled the span of its largest predecessor. Othmar H. Ammann (Hon. M. ASCE) directed the planning, design and construction. This bridge connects Fort Lee, N.J. with New York City, N.Y. | 1981 |
| Going-to-the-Sun Road, Lake McDonald, Montana, USA * ‡ When completed in 1932, this was the first major trans-mountain scenic highway in the United States. In carrying the road over the Continental Divide at Logan's Pass, its civil engineers had to overcome diverse and difficult design and construction challenges, and in doing so, established the engineering principles for future roads in national parks as well as principles that included precedents for environmental sensitivity for "roads that lay lightly on the land." These principles have been refined and applied by the Bureau of Public Roads (now Federal Highway Administration) and the National Park Service in many park roads and parkways throughout the United States. | 1985 |
| Golden Gate Bridge, San Francisco, California, USA Put in service in 1937, this world-renowned bridge, conceived by Joseph Strauss and designed largely by Charles Ellis, was the longest single span (4,200 feet) in the world for a quarter century. | 1984 |
| Goodyear Airdock, Akron, Ohio, USA * Completed in 1929, this unique structure, with a volume of 55,000,000 cubic feet, was the largest building in the world in terms of uninterrupted space. This required pioneering studies in the aerodynamics of buildings as well as the application of unusual engineering innovations. | 1980 |
| Gosport Naval Dry Docks, Norfolk, Virginia, USA * ‡ Built between 1827 and 1833, this and the Charlestown Naval Dry Dock, Boston, Massachusetts are two of the earliest major structures of their type in the United States. Despite the lack of scientific knowledge of hydraulics and geotechnology at the time, Loammi Baldwin II and his associated engineers successfully completed these projects, which served the U.S. Navy for well over a century. | 1977 |
| Gota Canal, Sweden Directed by Baltzer von Platen, sixty thousand workers built the Gota Canal between 1810 and 1832. The transnational canal has fifty-eight locks and sixty-five bridge spans over the 190 kilometer "Blue Ribbon" waterway. Baltzer von Platen engaged Thomas Telford, the first president of the Institution of Civil Engineers in London, as an advisor. | 1998 |
| Grand Coulee Dam, Grand Coulee, Washington, USA * Completed in 1941, this gravity dam is the largest concrete structure and hydroelectric facility in the United States. This project also provides primary flood control for the entire Columbia River basin, and offers significant irrigation and recreation benefits. | 1997 |
| Granite Railway, Quincy, Massachusetts, USA * This unique project, completed in 1826 before the advent of steam locomotives, first demonstrated the engineering advantages of rail transport in America, and introduced many technical features such as switches, the turntable and the double-truck railway car. | 1975 |
| Great Falls Raceway and Power System, Paterson, New Jersey, USA * ‡ The basis of the oldest (circa 1800) American integrated water power, industrial development and urban planning system. (Jointly designated with the American Society of Mechanical Engineers.) | 1977 |
| Great Western Railway, Bristol, England Built between 1835 and 1841, the Great Western Railway was the first major civil engineering work to be completed by its designer Isambard Kingdom Brunel (1806 - 1859). The original terminus, Bristol Temple Meads Station, was opened on August 31, 1840 and the whole line, Bristol to Paddington, opened on June 30, 1841. Brunel was an outstanding innovator and engineering genius. Notable works still surviving on the line include Box Tunnel, Sonning Cutting, Maidenhead Bridge, the Wharncliffe Viaduct, and Paddington Station. | 2005 |
| Gunnison Tunnel, Montrose, Colorado, USA The tunnel was the key to the first major trans-mountain irrigation system in the United States. When completed in 1909, it was the longest irrigation tunnel in America. The 30,582-foot tunnel initially supplied irrigation water to 146,000 acres of cropland. | 1972 |
| Hagia Sophia, Istanbul, Turkey Built under Justinian's direction from 532 to 537 and named the Church of the Holy Wisdom, the Hagia Sophia has four massive piers for east/west arches 19.8 m high with north/south buttresses to support the dome's diameter of 30.5 m. The dome is among the largest in the world. | 2000 |
| Hanford B Reactor, Richland, Washington, USA ‡ Designed and built as a part of the Manhattan Project during World War II, this reactor was the world's first full scale nuclear production facility. Built in only fifteen months during 1943-44, its design and construction required a team of nuclear physicists, chemical engineers, mechanical engineers, and civil engineers working together to overcome the many problems associated with a new and untried technology. The teamwork developed during this project served as a model for many future projects, such as the peaceful development of nuclear power and the space program. | 1993 |
| High Bridge, Jessamine, Kentucky, USA * Known as the first major cantilever bridge in the United States, this span was built between 1876-1877 by Charles Schaler Smith, and was the highest (275-feet) and longest span cantilever (three 375-foot spans) in the world at that time. The structure utilized portions of an earlier uncompleted bridge, designed by John A. Roebling in its construction. High Bridge was replaced, because of increases in train loads, by a bridge of similar construction in 1911 by Gustav Lindenthal, (Hon.MASCE). The 1911 bridge is still in service for the Norfolk Southern Railway. | 1985 |
| Hohokam Canal System, Phoenix, Arizona, USA * The Hohokam canal system is a significant pre-Columbian example of modification of the environment for beneficial use by Native Americans. This extensive irrigation system, constructed and utilized by the Hohokam Indians between 600 - 1450 A.D., foreshadowed by several centuries the important role that modern civil engineering was to play in the agricultural development of the western United States. | 1992 |
| Holland Tunnel, Jersey City/New York City, New Jersey/New York, USA This tunnel's twenty-nine foot diameter tubes were shield driven through extremely difficult river bottom conditions that were overcome by the ingenuity and determination of its engineers, Clifford M. Holland, Milton H. Freeman and Ole Singstad. When completed in 1927, this twin-tube subaqueous highway tunnel which runs from Jersey City, N.J. to New York City, N.Y., with its unprecedented length of 8,500 feet, was a bold step forward in navigable waterway crossings. | 1982 |
| Hoosac Tunnel, North Adams, Massachusetts, USA When completed in 1875, the Hoosac Tunnel was the largest and longest transportation tunnel in the Western Hemisphere. Many major rock tunneling innovations, such as the use of steam drills and nitroglycerin, were employed successfully on this project. The use of a central ventilation shaft as a construction shaft to provide two additional work faces was another remarkable engineering feature used in its construction. | 1975 |
| Hoover Dam, Boulder City, Nevada, USA ‡ Completed in 1935, this dam was designated one of "America's Seven Modern Civil Engineering Wonders" in 1955. This 726-foot high arch gravity structure was the greatest constructed at that time and remains the highest concrete dam in the Western Hemisphere. It continues to generate unparalleled benefits to the nation through regulation of the Colorado River for water conservation (fulfilling international commitments), power production, flood control, recreation, and fish and wildlife enhancement. | 1984 |
| Horseshoe Curve, Pennsylvania, USA Designed and built under the direction of Pennsylvania Railroad chief engineer and, later, company president, J. Edgar Thomson, Horseshoe Curve opened February 15, 1854. It is 549 meters across and 805 meters long with a 1.8 percent grade. Eliminating the Portage Railroad's ten incline planes greatly encouraged east-west trade crossing the Allegheny Mountains. | 2003 |
| Houston Ship Channel, Houston, Texas, USA The Houston Ship Channel, originally constructed in 1837, has been under continuous development since that time. The main channel, about fifty miles long, is directly linked to hundreds of transportation facilities, industrial plants, and other enterprises that use the channel to ship products to markets throughout the world. | 1987 |
| Hudson and Manhattan Railroad Tunnel, Jersey City/New York City, New Jersey/New York, USA The original Hudson River tunnel crossing was begun in 1874 and construction was completed in 1908 connecting Jersey City, N.J. with New York City, N.Y. It was the first railroad tunnel under a major river in the country and introduced shield-system of subaqueous tunneling to the United States. Acclaimed internationally at its opening, it serves millions of commuters each year. | 1978 |
| Hwaseong Fortress, Suwon City, Republic of Korea The Hwaseong Fortress was designed by the builder/scholar Jeong Yak-Yong and built from 1794 to 1796. Hwaseong Seong-yeokuigwe is a unique ten-volume work that documents its construction. The rapid construction of the fortress, using paid labor, symbolizes the cultural and technological renaissance under King Jeongjo. | 2004 |
| Hydraulic-Inclined Plane System of the Morris Canal, Stanhope, New Jersey, USA This system was the key civil engineering feature which permitted the successful completion of the Morris Canal project in 1831. The bold concept of using water turbine power to supply the energy necessary to lift canal boats over the 914-foot topographic barrier was a technical feat conceived by engineering consultant Professor James Renwick. It enhanced American engineering prestige worldwide. | 1980 |
| Hydraulics Laboratory at the University of Iowa, Iowa City, Iowa, USA The Hydraulics Laboratory at The University of Iowa, renovated in 2001 and in 2003 renamed the C. Maxwell Stanley Hydraulics Laboratory, is the oldest university-based hydraulics laboratory in the U.S. that continuously has focused on research, education, and service in hydraulic engineering. Since its initial construction in 1919, the facility and staff have produced a massive amount of research that has shaped water-related constructs around the world. Its efforts have been guided by noted directors such as Floyd Nagler (1920-1933), Hunter Rouse (1944-1965), and John F. Kennedy (1966-1991). Students trained here have come from and practiced around the world. The building provides the home base for IIHR-Hydroscience & Engineering, formerly the Iowa Institute of Hydraulic Research. | 2005 |
| Ifugao Rice Terrace, Banaue, Philippines Dating from 100 BC, this is the oldest and most extensive use of terraces in the world. The 20,000 hectares of terraces represent a rearrangement of the Cordillera Mountain Range from bedrock to topsoil. The engineering principles of hydrology, sustainable development, and efficient use of water resources and irrigation are all embodied in the careful design of this ancestral land management program. | 1995 |
| Ingalls Building, Cincinnati, Ohio, USA This building, completed between 1902 and 1903, was the first reinforced-concrete skyscraper in the world. A 16-story (210 feet) structure, it demonstrated for the first time the safety and economy of reinforced-concrete frames for high rise construction. It was a vital stimulus for the use of reinforced concrete as a fireproofing structural material. | 1973 |
| International Boundary Marker #1, El Paso, Texas, USA This marker, located between Dona Ana County, New Mexico (near El Paso, Texas) and Juarez, Mexico, not only represents an international boundary but is also a monument to the professional skills of the American surveyors who were called upon to locate it in 1855. | 1976 |
| Ironbridge, Coalbrookdale-Ironbridge, England This bridge, completed in 1779, is recognized as the first iron bridge in the world. Standing today, it is an outstanding international monument to both the civil engineering profession and the industrial revolution. | 1979 |
| Iron Building of the U.S. Army Arsenal, Watervliet, New York, USA * Completed in 1859 by James Bogardus, this half-acre military storehouse is an outstanding example of the civil engineer's skill and the iron master's art in the the mid 19th century. Built entirely of cast iron and wrought iron elements, it is believed to be the oldest all-metal building in the United States. The Iron Building remains in service as a warehouse housing the Arsenal's Ordinance Museum. | 1983 |
| John A. Roebling Bridge, Cincinnati, Ohio, USA * ‡ When completed by John A. Roebling in 1866, this suspension bridge, with a main span of 1,057 feet, was the greatest structure of its kind in the world and was the prototype for his greatest achievement, the Brooklyn Bridge, which followed sixteen years later. This bridge, due to renovations, has remained in continuous service since its opening, even in 1937 when the Ohio River rose eighty feet. | 1982 |
| Joining of the Rails - Transcontinental Railroad, Promontory, Utah, USA * ‡ On May 10, 1869, the completion of the 1,776 miles of trunk line railroad over the mountains and deserts of the continent marked a turning point in American history by signaling the opening of the West and the emergence of a unified nation. | 1968 |
| Kamehameha V Post Office, Honolulu, Hawaii, USA Designed by J.G. Osborn and completed in 1871, this structure is the oldest public building in the United States to incorporate structural elements of reinforced portland cement concrete. | 1987 |
| Kansas City Park and Boulevard System, Kansas City, Missouri, USA This pioneer project, completed between 1893 and 1915, was among the first to integrate the aesthetics of landscape architecture with the practicality of city planning. Not only did the Kessler plan, a system of parks connected by scenic boulevards, provide the people of Kansas City with close contact with the natural environment amid the urbanized area, but it also stimulated other metropolitan areas to undertake similar projects. | 1974 |
| Kavanagh Building, Buenos Aires, Argentina This thirty-one story structure, complete with central air conditioning and advanced technology, was one of the first reinforced concrete skyscrapers in the world when opened in 1935. It remained the tallest building in South America for many years. | 1994 |
| Kentucky Dam, Gilbertsville, Kentucky, USA The Kentucky Dam, completed in 1944 at mile 22.4 on the Tennessee River, is the key structure in the Tennessee Valley Authority (TVA) system. Not only does it play an important role in the reduction of flood crests on the lower Ohio and Mississippi Rivers, but the construction process also involved the first successful use of ground freeze stabilization for an open vertical shaft, and made pioneering use of extensive aerial photography. In addition, the project contained the largest single lift lock on any United States inland river at the time of its construction. | 1996 |
| Keokuk Hydro-Power System, Keokuk, Iowa, USA This privately-financed enterprise was placed in operation in 1913. At that time the Keokuk project incorporated the longest monolithic concrete dam in the world and was a pioneering effort in large-scale, low-head hydroelectric power. | 1988 |
| King's Road, New Smyrna, Florida, USA When completed between 1766 and 1775, King's Road was the principal overland transportation link between the former British Colony of St. Augustine, and the thirteen colonies. The original road of 126 miles was a remarkable engineering feat passing through the swampy flatlands of coastal Florida and over rivers and streams. | 1976 |
| Kinzua Railway Viaduct, Kane, Pennsylvania, USA * Constructed in only 102 days and completed in 1882, this structure was by far the highest (302 feet) and the longest (2,053 feet) viaduct in the world at that time. Reinforced in 1900 because of heavier service loads, the new bridge included the first Vierendeel type truss in the western hemisphere. Octave Chanute (1891 ASCE President) participated in the engineering of both structures. | 1982 |
| Lacey V. Murrow Bridge and Mount Baker Ridge Tunnels, King County, Washington, USA These structures constitute the world’s first reinforced concrete floating bridge - the largest floating structure ever built - and the largest diameter soft-earth tunnels when completed in 1940. This project greatly reduced highway travel time and distance to Seattle from the east and led to the construction of other major floating bridges in the United States, Canada, Norway, and Japan. Civil engineer Homer Hadley conceived this unique application for concrete and civil engineer Lacey V. Murrow led project design and construction. Contractors were Pontoon Bridge Builders for the bridge and Bates and Rogers for the tunnel. The bridge pontoons were replaced during rehabilitation in 1993. | 2008 |
| Lake Moeris Quarry Road, Egypt This road is recognized as the oldest surviving paved road in the world. Dating from the Old Kingdom period in Egypt (2575-2134 BC), it transported basalt blocks from the quarry to a quay on the shores of ancient Lake Moeris. It was paved with large slabs of limestone and sandstone, of which approximately 47% of its total length of 11.7 km remains. | 1996 |
| Lake Washington Ship Canal & Hiram M. Chittenden Locks, Seattle, Washington, USA Conceived and built by the U.S. Army Corps of Engineers between 1911 and 1917, these heavily utilized locks, the largest on the West Coast, incorporated unique, parallel dual-sized lock chambers for water conservation and preventive measures to reduce salt water intrusion into Lake Washington. | 1997 |
| Lawrence Experiment Station, Lawrence, Massachusetts, USA Established in 1886, the Lawrence Experiment Station was a pioneer engineering laboratory dedicated to research on the treatment of water supply, sewage and industrial waste. The station's contribution to the field of environmental engineering has been outstanding both nationally and internationally.[Renamed the Senator William X. Wall Experiment Station in 1993] | 1975 |
| Louisville and Portland Canal Locks & Dam, Louisville, Kentucky, USA The original canal and locks constructed at this site in the first half of the 19th century were responsible for permanently changing navigation on the Ohio River. The original locks and their successors improved the transportation of people and goods towards St. Louis, New Orleans and points west and played an important role in the settlement and growth of the nation. | 2002 |
| Louisville Water Works, Louisville, Kentucky, USA ‡ When constructed between 1875 and 1896 by Charles Hermany (1904 ASCE President), this project demonstrated the practicality of rapid sand filtration on a municipal scale, and was a major milestone in American sanitary engineering. | 1981 |
| Lowell Waterpower System, Lowell, Massachusetts, USA * ‡ A network of power canals with a highly sophisticated controlled and measured distribution system, when work commenced in 1821, this was a pioneer water development scheme. The network was continually expanded and improved until the 1880's when electrical energy was introduced. The early industrial development of the Northeast was greatly enhanced by application of this original civil engineering concept, leading to the emergence of the famous mill towns of New England and elsewhere. For many years the principal engineer of this enterprise was James Bischeno Francis (1881 ASCE President). | 1984 |
| Machu Picchu, Machu Picchu, Peru A masterpiece of site selection, city planning, design and construction of trails, buildings, a water supply canal with many fountains, and agricultural terraces, the Machu Picchu infrastructure illustrates the advanced civil, hydraulic, and geotechnical engineering capabilities of the Inca people. The steep agricultural terraces, fine masonry walls, surface and subsurface drainage, and the spring headworks are all excellent examples of Inca civil engineering. | 2006 |
| Maine Turnpike, Maine, USA The Maine Turnpike, opened in 1947, was the first superhighway in New England and the second modern toll highway in the United States. Financed entirely by revenue bonds issued by the Maine Turnpike Authority to be paid solely from toll revenues, it was the first major modern highway built without any state or federal funding. | 1999 |
| Marlette Lake Water System, Virginia City, Nevada, USA Constructed from 1873 to 1887, the Marlette Lake Water System was the first American system developed to overcome mountainous topography. This system's inverted siphon, sustaining a head of over 1,700 feet, was the greatest in the world by a factor of two. | 1975 |
| Marshall Building, Milwaukee, Wisconsin, USA A pioneer of reinforced concrete construction, Claude A.P. Turner designed the Marshall Building's structure. It is the oldest extant example of Turner's "mushroom" flat-slab system, which transformed the design and construction of reinforced concrete floors worldwide. | 2002 |
| Mason-Dixon Line, Maryland-Pennsylavania, USA This world-famous line, completed in 1767, established the highest standards for engineered surveys in its delineation of the boundary lines between Delaware, Maryland, Pennsylvania and Virginia. | 1977 |
| McNeill Street Pumping Station, Shreveport, Louisiana, USA The station is a self-contained lesson in the history of municipal water system development. From high-volume pumping technology to water filtering and disinfection, it helped introduce or refine key technologies that were central to the evolution of America's urban water supply. This facility was Louisiana's second waterworks and provided potable water for Shreveport for over a century (1887-1994). It was the last facility in the United States to use steam power to distribute water to a major city and is the only remaining steam-power water treatment plant with much of its antique equipment still intact. | 1999 |
| Menai Suspension Bridge, Menai, Wales Built for the Chester-Holyhead Railway, this bridge was a major structure on the road connecting London with Holyhead and by sea to Ireland. The bridge had the world's longest span and greatly advanced suspension bridge development. | 2002 |
| Miami Conservancy District, Dayton, Ohio, USA This project, completed in 1922, was the first regionally coordinated flood control system in the United States embodying retention reservoirs for controlled release of floodwaters. The actual project consisted of the construction of five dams, as well as levee and channel improvements of nine villages and towns. It also included the relocation of four railroad lines and of many highways and wire lines, the removal of one village, the lowering of water and gas mains, and the overcoming of many other obstacles. Since its completion, there has been no flood damage to the protected Miami Valley. | 1972 |
| Middlesex Canal, Lowell, Massachusetts, USA * The canal is one of the oldest man-made waterways in the United States. Begun in 1794 and completed in 1803, the canal stretched twenty-seven miles from what was to become Lowell, to Charlestown, Massachusetts. Twenty locks and nine aqueducts were designed and constructed along the route. The canal served as a model for the later Erie Canal and was the first in the country to prove the practicality of canal transportation by low freight rates and expansion of traffic. It was designed and constructed by Col. Loammi Baldwin. | 1967 |
| Milwaukee Metropolitan Sewage Treatment Plant, Milwaukee, Wisconsin, USA * Started in 1919, this is America's earliest large-scale activated sludge type municipal sewage treatment plant. Because activated sludge proved to be a more successful method of environmental recycling, this plant was a major improvement over other contemporary treatment methods and an advance in municipal sanitary engineering. Many other municipalities have adopted its system of sewage treatment. | 1974 |
| Minot's Ledge Lighthouse, Cohasset, Massachusetts, USA This lighthouse, built between 1855 and 1860, successfully served mariners for over 116 years. It was engineered by Joseph G. Totten (Hon.M.ASCE) and was internationally recognized as an outstanding achievement in the civil engineering design and construction of a structure to resist open-sea wave forces. | 1977 |
| Missouri River Bridges, Chamberlain, South Dakota, USA Five Pratt truss steel bridges, completed between 1924 and 1926, constituted the first Missouri River highway crossings in South Dakota. Designed for economy and endurance by the South Dakota Highway Commission, only the Chamberlain Bridge remains in service. It now includes trusses from the original Wheeler Bridge. Subsequent Missouri River dams made the river too wide for the original structures. | 1994 |
| Moffat Tunnel, Winter Park, Colorado, USA Beginning service in 1928, this 6.2 mile Rocky Mountain tunnel, located sixty miles west of Denver, Colorado, was not only the largest railroad tunnel in the Western Hemisphere when completed, but also demonstrated new tunnel construction techniques and the innovative concept of using its pilot bore later as a permanent aqueduct. | 1979 |
| Montgomery Bell's Tunnel, Nashville, Tennessee, USA * ‡ As the earliest (1818) known rock tunnel of significant size in the United States, it served as a guide to early American civil engineers and thus can be said to be the precursor to later American tunneling accomplishments. | 1981 |
| Morison's Memphis Bridge, Memphis, Tennessee, USA Erected in 1892 by George S. Morison (1895 ASCE President), this cantilever truss was built entirely of the then-newly-developed basic open hearth steel. When completed, its 790-foot main span was the longest railroad truss in North America. The bridge is now called the Frisco Bridge. | 1987 |
| Mormon Tabernacle, Salt Lake City, Utah, USA * ‡ Completed in 1867, with 150-foot wooden lattice arches, the design and construction of this structure's roof was an engineering challenge. A railroad had not yet been completed that could bring metal building components from the industrialized centers in the East. Stone and lumber building materials were obtained from surrounding mountains. Few changes have been made in the original construction, and the roof remains structurally sound. | 1971 |
| Moseley Wrought Iron Arch Bridge, North Andover, Massachusetts, USA Designed, patented, and built by Thomas W.H. Moseley in 1864, this arched ninety-six foot span bridge incorporated for the first time in the United States the use of riveted wrought iron plates for the triangular-shaped top chord and preceded by years the standard use of wrought iron for bridges. | 1998 |
| Mount Washington Cog Railway, Mt. Washington, New Hampshire, USA When completed in 1869 this was the first mountain climbing railway in the world. Its cog rail system allows the railway to overcome grades exceeding 37 percent. Still in service this world-renowned project clearly demonstrated the ability of the American engineer to provide innovative and economical solutions to unusual and difficult problems. (Jointly designated with the American Society of Mechanical Engineers.) | 1975 |
| Mullan Road, Walla Walla, Washington, USA * This road, surveyed between 1853 and 1854 and constructed between 1858 and 1862, was the first major engineered highway in the Pacific Northwest. Its 624 miles connected the Missouri River Basin to the Columbia River Basin, thereby greatly accelerating the development of the Northwest as an integral part of the United States. | 1977 |
| Muskingum River Navigation System, Zanesville, Ohio, USA The Muskingum River Improvement, started in 1837, played a key role in economic development of the Greater Ohio River Valley as one of the nation's first complete slackwater navigation systems for steam powered vessels, and survives as the most intact system of large hand-operated locks in the United States. | 2000 |
| National Road, New Concord, Ohio, USA Constructed between 1811 and 1839, this highway, surveyed by Jonathan Knight and Josiah Thompson, was the precursor of today's federal interstate system and represented the highest standards of road design and construction of its time. | 1976 |
| Navajo Bridge, Page, Arizona, USA This 616-foot main span, three-hinged, braced spandrel steel arch bridge was completed in 1929, and for the next sixty-six years it served as the only crossing of the Colorado River for six hundred mil | |