Shows geologic formations. "Surveyed in 1877." Relief shown by contours and spot heights. To accompany the Survey's 12th annual report (1878). "56"--Lower right margin.
Creator:
Geological and Geographical Survey of the Territories (U.S.)
Publisher:
[Washington, D.C. : The Survey ; New York, N.Y.] : Julius Bien, Lith., [1878]