2010. National Geophysical Data Center. This line shapefile shows lines of equal vertical intensity of the Earth's magnetic field, derived from the International Geomagnetic Reference Fie... National Atlas of the United States.
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1999. Geological Survey (U.S.). This line shapefile portrays the major roads in the United States, Puerto Rico, and the U.S. Virgin Islands. The file was produced by joining the i... Geological Survey (U.S.).
1879. United States. Army. Office of the Chief of Engineers. Shows railroads.; Relief shown by hachures. 80 x 72 centimeters Scale approximately 1:1,520,640 not 1:1,500,000 General Map Collection. U.S. Army? (Washington, D.C.?).
1869. United States. Army. Department of California (1865-1913). Relief shown by hachures and spot heights.; "Reconnaissance maps, Department of California."; "Officially compiled and published at the Engineer Of... Photolith. by the N.Y. Lithograph & Print. Co (New York).
2004. National Atlas of the United States. This polygon shapefile portrays county level data for the fiscal-year-2004 National Fire Plan - Hazardous Fuels Reduction Program. The purpose of t... National Atlas of the United States.
1972. National Atlas of the United States. This polygon shapefile contains National Wilderness Preservation System areas of 640 acres or more, in the United States, Puerto Rico, and the U.S.... National Atlas of the United States.
1925. United States. Bureau of Reclamation. Relief shown by hachures and spot heights.; Map no. 21444.; Includes text. 25 x 31 Centimeters Scale approximately 1:400,000 General Map Collection. Bureau of Reclamation (Washington, D.C).
2004. Instituto Nacional de Estadística, Geografía e Informática (Mexico), Canada Centre for Mapping, and Geological Survey (U.S.). This polygon shapefile contains bathymetric data with depth in metres for ocean areas covered by the extent of the North American Atlas project. Is... Canada Centre for Mapping.
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.
1924. Geological Survey (U.S.). Relief shown by contours and spot heights.; Index map on each sheet. each sheet 54 x 69 centimeters or smaller Scale 1:31,680 General Map Collection. The Survey (Washington, D.C).