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A "quadrangle" is a topographic map produced by the United States Geological Survey (USGS) covering the United States. The maps are usually named after local physiographic features. The shorthand " quad " is also used, especially with the name of the map; for example, "the Ranger Creek, Texas quad".
In 2008 the USGS abandoned traditional methods of surveying, revising, and updating topographic maps based on aerial photography and field checks. [33] Today's U.S. Topo quadrangle (1:24,000) maps are mass-produced, using automated and semiautomated processes, with cartographic content supplied from the National GIS Database. [33]
Topographic maps are also commonly called contour maps or topo maps. In the United States, where the primary national series is organized by a strict 7.5-minute grid, they are often called or quads or quadrangles. Topographic maps conventionally show topography, or land contours, by means of contour lines.
The Archive includes each U.S. state and territory, in all scales, editions and various printings. With coverage dating from the 1880s when the USGS began publishing standard topographic quadrangles, the Archive is the most complete collection of USGS topographic maps.
During the registration process, prospective volunteers submitted a list of the 7.5 minute quadrangle maps on which they wished to work. Once accepted into the project, volunteers received their assignment and 1:24,000 scale topographic map of their quad. While there was no deadline for completing maps, the project's administrators preferred ...
DOQs produced by the USGS cover an area measuring 7.5-minutes longitude by 7.5-minutes latitude (the same area covered by a USGS 1:24,000-scale topographic map, also known as a 7.5-minute quadrangle) or 3.75-minutes by 3.75-minutes.
This 1988 BLM map depicts the principal meridians and baselines used for surveying states (colored) in the Public Land Survey System.. The Public Land Survey System (PLSS) is the surveying method developed and used in the United States to plat, or divide, real property for sale and settling.
Figure 1. This BLM map depicts the principal meridians and baselines used for surveying states (colored) in the PLSS.. The following are the principal and guide meridians and base lines of the United States, with the year established and a brief summary of what areas' land surveys are based on each.