The 1870s was a period of intense effort, by such prominent people as Clarence King, Ferdinand Hayden, and John Wesley Powell, to advance the geographical knowledge of the West. These various surveys presented a threat to the Army's supremacy in the field of mapping and to the related appropriations from Congress. As a result of these pressures, the Army Corp of Engineers developed a plan to systematically survey the entire West to be called the U.S. Geographical Surveys West of the One Hundredth Meridian. The region was divided up into 95 rectangles, with atlas sheets to be prepared for each, comprising an area 2°45' of longitude and 1°40' of latitude on a scale of eight miles to the inch. Lieutenant George Wheeler was chosen to head this immense project. Surveys were conducted each summer from 1872 to 1878, after which Congress cut off appropriations for field work; thus the survey was not completed as originally envisioned. Wheeler published annual reports from 1873 to 1884, as well as the final Geographical Report published in 1889. The maps from this report are a valuable document of the record of Western exploration.

This map was the result of Wheeler's spectacular exploration of 1871. The Interior Department's civilian surveys by Powell and Hayden posed a major threat to funding for military mapping and exploration efforts. Wheeler, barely 30 years of age, was tasked to gather information and produce a highly accurate map of the area. He accomplished this and in so doing conceived of the U.S. Geographical Surveys West of the One Hundredth Meridian, of which this map is the forerunner. The map is very detailed, with scores of mining districts located and named. Locates Prescott, St. George, San Bernardo, Elko, Ely, and Tucson. Wheat refers to it as a "map of great interest." The map displays a portion of Nevada together with parts of California, Utah and Arizona, as bounded by Tucson, San Bernardino and the Sierra Nevadas, St. George, and north to Mountain City, above Elko. Topography shown via hachure. A very nice example of this increasingly difficult to find map

References: Wheat [TMW] 1237.

Condition: B

Nice impression with full margins. Hint of toning and scattered foxing. Issued folding, now pressed and backed with Japanese tissue to reinforce some edge tears. Some paper added to the binding side to create an even margin with a 3" well-closed tear at binding trim.