All materials are from the U.S. Geological Survey.
   Miscellaneous Investigations Series Map I-2206
   By Gail P. Thelin and Richard J. Pike
   Landforms of the Conterminous United States -
   A Digital Shaded-Relief Portrayal,1991.

Images
   Large image   [ 11.8 MB, .tif ]
   Large image   [ 2.9 MB, .pdf ]
   Accompanying pamphlet   [ 7 MB, .pdf ]

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