Maps

Trails and symbols are shown clearly. A comprehensive legend appears on each map. Since each map is unique, placement of the legend varies.  
The USGS Field Records Library in Denver, Colorado, has an extensive collection of materials. Many of the field records are online at http://www.cr.usgs.gov/. You may contact them at: USGS Field Records LibraryBox 25046, MS 914Denver Federal...
If coordinates are to be passed on to another person it is technically necessary to report the horizontal datum and the latitude/longitude of the point (e.g. NAD 27 CONUS, 44 degrees, 7 minutes, 30 seconds north/ 104 degrees, 15 minutes, 10 seconds west...
Generally, for the conterminous United States, the North American Datum (NAD) shift amounts to about 210 meters. This shift occurs because of the change in shape of the spheroid used to define the datum. The GRS 80 spheroid (used for NAD 83) is shorter...
The distances vary. A degree, minute or second of latitude remains fairly constant from the equator to the poles; however a degree, minute, or second of longitude can vary greatly as one approaches the poles (because of the convergence of the meridians...
Yes, the National Atlas offers plenty of choices in page-size maps. Please see our Printable Maps page for the latest list of the printable maps we offer. In addition, the following sites have links to United States maps in formats appropriate for...
Forest Visitor Maps are at a smaller scale than USGS topographic quadrangle maps and typically do not show contours. Forest Visitor maps contain general recreational information about things such as camping, fishing, biking, other activities, points of...
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Digital line graph (DLG) data are digital representations of cartographic information. DLG's of map features are digital vectors converted from maps and related sources. The U.S. Geological Survey (USGS) DLG data are classified as large, intermediate,...
The National Geologic Map Database Data Portal is intended to: 1) give the user a quick browse and query of our Nation's geologic maps, in a standardized format, and 2) link the user to the source information found via the NGMDB Map Catalog and Geologic...