This exceptionally detailed map illustrates the topographical features of the northwestern Great Plains region extending from the Canadian border south to Pikes Peak, Colorado, and from the Colorado Front Range east to Leavenworth, Kansas. It is a compilation of numerous surveys and explorations in the region, including those of the Government Land Office, Pacific Railroad Surveys, Stansbury, Fremont, Nicollet and many others. Wheat notes that while the map was "made to show Lieutenant Warren's explorations, the many other explorers' routes, carefully shown, and particularly General Harney's route, give this map a position that is notable among all those of this period." First published in 1858, the map is also noteworthy for its early depiction of a "Gold Field" along the Colorado Front Range in the vicinity of Auroria, near the then-future home of Denver. Other details include Indian ranges, reservations, forts, proposed roads, land descriptions, and much more. Lithographed by Norris Peters. Accompanied by the 125-page report (6.0 x 9.0"). The map and report are housed in archival paper covers.

This map served as the topographical base for F. V. Hayden's geological map of Nebraska and Dakota provided with his Final Report of the United States Geological Survey of Nebraska published in 1872.

References: Wheat (TMW) #1005.

Condition: B+

Issued folding on a bright sheet with numerous fold separations that have been mostly closed on verso with archival tape. There are a couple of tiny chips along the fold lines at right with minor loss of image. Report text is lightly toned, and the front paper wrapper is missing.