The GIS Surface Effects Map Archive contains a comprehensive collection of maps showing the surface effects produced by underground nuclear testing at the Nevada Test Site. From 1951 to 1992, scientists with the U.S. Geological Survey and agencies of the U.S. Department of Energy used field and aerial-photo mapping techniques to painstakingly map such surface effects as collapse sinks, craters, cracks, fractures, faults, and pressure ridges. Shortly after each test, a complex surface effects map was produced. Of the more than 920 underground detonations conducted at the Nevada Test Site, 688 were mapped for surface effects. This archive preserves these original maps in digital format. A Geographic Information System (GIS) was used to digitally reproduce each original, hand-drawn surface effects map and to assemble these maps into the digital data sets of this archive. The archive was designed to allow easy access to the maps, while preserving the original maps for perpetuity. Users can query the detonation sites database; prepare, view, and print individual or composite maps; and perform various types of scientific analysis and management tasks. Spatial analyses and queries can be performed on detonation sites and related surface effects in conjunction with other chronological, geographical, geological, or hydrological information via links to external maps and databases. This browser interface provides information about the archive, the history of surface effects mapping at the Nevada Test Site, the methods used to produce the digital surface effects maps, and links to published reports, data tables, and maps. Location maps show testing areas, operational areas, and detonation sites. Demonstration maps illustrate the methods used to produce the digital surface effects maps and exhibit some of the characteristics and uses for these data. Use the links below to view and print individual surface effects maps, retrieve information about the detonations and types of surface effects produced, and to learn about the organization and intended use of the map data contained in the archive.