Charged with the "classification of the public lands and examination of the geological structure, mineral resources, and products of the national domain," the U.S. Geological Survey was established by Congress on March 3, 1879. In the 125 years since, the USGS continually has evolved through technological advancements and adapted to changing scientific needs and agendas. The tasks of classifying public lands - originally meaning land west of the Allegheny Mountains - into mineral and nonmineral, and examining mineral resources eventually broadened to include developing topographic maps, analyzing water resources, and identifying natural hazards. Today, civil engineers often rely upon USGS products to provide the backdrop for land development, water resource, transportation, and waste management projects, among others.
USGS celebrates 125 U.S. Geological Survey A USGS topographer works with a planetable in the early 1900s on the summit of Post Peak in Yosemite National Park, Calif. The photo and corresponding map above from 1906 show Half Dome,also in Yosemite.
Clarence King, the first director of the USGS, appointed topographers within the Division of General Geology. (There also was a Division of Mining Geology.) It was the Survey's second director, John Wesley Powell, famed Grand Canyon explorer, who made topographic work independent of geologic studies. Powell considered geology a part of geography and was primarily concerned with landforms and land use, according to a history compiled by the USGS (Circular 1050).
In 1882, after Congress authorized Powell to continue preparing a geologic map of the United States - which extended the scope to include the eastern states - he redirected topographic work toward preparing a base map. Topographic mapping became the largest part of the USGS program at the time.
Following a drought in 1866, Congress again extended the Survey's scope of work by authorizing studies to determine the potential for irrigating arid Western lands and to select sites for water storage reservoirs and flood control. Powell subsequently planned topographic surveys to define catchment basins, hydrographic surveys to measure stream flow, and engineering studies to determine the feasibility of constructing reservoirs.
The irrigation study largely was discontinued in 1890, but under its third director, Charles Walcott, the USGS extended its geological studies in 1894 to include stream flow, groundwater, and water use. Also under Walcott's direction, topographic mapping was improved by placing it under Civil Service and by beginning the installation of permanent benchmarks. Previously, the topographic corps included many untrained and poorly trained workers, including relatives of congressmen.
By its 25th anniversary in 1904, the USGS had prepared topographic maps of 929,850 square miles (26 percent) of the United States, including Alaska. Mapping continued at a slow pace, as evidenced by the fact that by the end of World War I, 60 percent of the country still remained unmapped. Industrial development, power generation projects, and highway construction in the early 1920s increased the demand for topographic information.
The USGS formed a Section of Photographic Mapping in 1921, using images taken by a trilens aerial camera that Topographic Branch engineers had developed in 1917. They had been experimenting with the use of aerial photography since 1904. A Tennessee Valley Authority (TVA) project in 1933, however, offered the first full-scale test of aerial photography and newly developed photogrammetric equipment for topographic mapping.
TVA grants also helped support USGS research into the relation of rainfall to runoff, as well as the magnitude and frequency of floods. The USGS continued expanding and updating its stream gaging-station network and hydrologic studies to address problems posed by industrial development, urbanization, and increasing groundwater withdrawal. By its 75th anniversary in 1954, the USGS operated about 6,400 stream-gaging stations and was involved in 500 groundwater investigations.
USGS Circular 1050 by Mary C. Rabbitt (the reference for this article) provides a complete history of the USGS from 1879 to 1989. It is available on line at www.usgs.gov/125.
Read about design and construction of the Arlington Memorial Bridge in Washington,D.C., in the July 2004 issue of Structural Engineer.