The Geographic Names Information System (GNIS) is a database of name and location information about more than two million physical and cultural features throughout the United States and its territories, Antarctica, and the associated states of the Marshall Islands, Federated States of Micronesia, and Palau. It is a type of gazetteer. It was developed by the United States Geological Survey (USGS) in cooperation with the United States Board on Geographic Names (BGN) to promote the standardization of feature names.
Data were collected in two phases. Although a third phase was considered, which would have handled name changes where local usages differed from maps, it was never begun.
The database is part of a system that includes topographic map names and bibliographic references. The names of books and historic maps that confirm the feature or place name are cited. Variant names, alternatives to official federal names for a feature, are also recorded. Each feature receives a permanent, unique feature record identifier, sometimes called the GNIS identifier. The database never removes an entry, "except in cases of obvious duplication."
Original purposes
The GNIS was originally designed for four major purposes: to eliminate duplication of effort at various other levels of government that were already compiling geographic data, to provide standardized datasets of geographic data for the government and others, to index all of the names found on official U.S. government federal and state maps, and to ensure uniform geographic names for the federal government.
Phase 1
Phase 1 lasted from 1978 to 1981, with a precursor pilot project run over the states of Kansas and Colorado in 1976, and produced 5 databases. It excluded several classes of feature because they were better documented in non-USGS maps, including airports, the broadcasting masts for radio and television stations, civil divisions, regional and historic names, individual buildings, roads, and triangulation station names.
The databases were initially available on paper (2 to 3 spiral-bound volumes per state), on microfiche, and on magnetic tape encoded (unless otherwise requested) in EBCDIC with 248-byte fixed-length records in 4960-byte blocks.
The feature classes for association with each name included (for examples) "locale" (a "place at which there is or was human activity" not covered by a more specific feature class), "populated place" (a "place or area with clustered or scattered buildings"), "spring" (a spring), "lava" (a lava flow, kepula, or other such feature), and "well" (a well). Mountain features would fall into "ridge", "range", or "summit" classes.
A feature class "tank" was sometimes used for lakes, which was problematic in several ways. This feature class was undocumented, and it was (in the words of a 1986 report from the Engineer Topographic Laboratories of the United States Army Corps of Engineers) "an unreasonable determination", with the likes of Cayuga Lake being labelled a "tank". The USACE report assumed that "tank" meant "reservoir", and observed that often the coordinates of "tanks" were outside of their boundaries and were "possibly at the point where a dam is thought to be".
National Geographic Names database
The National Geographic Names database (NGNDB hereafter) was originally 57 computer files, one for each state and territory of the United States (except Alaska which got two) plus one for the District of Columbia. The second Alaska file was an earlier database, the Dictionary of Alaska Place Names that had been compiled by the USGS in 1967. A further two files were later added, covering the entire United States and that were abridged versions of the data in the other 57: one for the 50,000 most well known populated places and features, and one for most of the populated places. The files were compiled from all of the names to be found on USGS topographic maps, plus data from various state map sources.
In phase 1, elevations were recorded in feet only, with no conversion to metric, and only if there was an actual elevation recorded for the map feature. They were of either the lowest or highest point of the feature, as appropriate. Interpolated elevations, calculated by interpolation between contour lines, were added in phase 2.
