Search Results
2003. United States. Environmental Protection Agency. This polygon shapefile shows Omernik's Level III ecoregions, derived from a 1:7,500,000 map created by J.M. Omernik in 1987 and from refinements of... National Atlas of the United States.
2003. Geological Survey (U.S.). Water Resources Division. Wisconsin District. This polygon shapefile contains the shallowest principal aquifers of the conterminous United States, Hawaii, Puerto Rico, and the U.S. Virgin Islan... Geological Survey (U.S.).
2010. Geological Survey (U.S.). This polygon shapefile portrays the Public Land Surveys of the United States, including areas of private survey, donation land claims, and land gra... Geological Survey (U.S.).
2005. Geological Survey (U.S.). This map layer contains locations and information on faults and associated folds, in the United States, that are believed to be sources of signific... National Atlas of the United States.
2012. Rukstales, Kenneth S. (compiler). This polygon shapefile represents seismic hazards in the United States. The data represent a model showing the probability that ground motion will ... National Atlas of the United States.
1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, and 2005. United States. Agricultural Research Service. This polygon shapefile portrays the spread, by year, of the Africanized honey bee (AHB) in the United States, Puerto Rico, and the U.S. Virgin Isla... National Atlas of the United States.
1972, 1973, 1974, 1975, 1976, 1977, 1978, 1979, 1980, 1981, 1982, 1983, 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, and 2005. Geological Survey (U.S.). This polygon shapefile portrays the state boundaries of the United States, and the boundaries of Puerto Rico and the U.S. Virgin Islands. The map l... Geological Survey (U.S.).
1972, 1973, 1974, 1975, 1976, 1977, 1978, 1979, 1980, 1981, 1982, 1983, 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, and 2005. National Atlas of the United States. This polygon shapefile portrays the time zones of the United States, Puerto Rico, and the U.S. Virgin Islands. Also included are the Greenwich Mean... National Atlas of the United States.
2001. Geological Survey (U.S.). This data set includes a selection of urban areas in the United States derived from the urban areas layer of the Digital Chart of the World (DCW). ... Geological Survey (U.S.).