WHEELER, G. U. S. Geographical surveys west of the one-hundredth meridian. Topographical atlas. Washington, 1878. Imprimé en couleurs. Paper cover serving as title page (cut out) and 11 large folio maps, including one large folding map, "Topographical Map of Lake Tahoe…" (104 × 870 cm), with a 10 cm tear along the center, a small hole at the fold intersection, and a marginal tear at the lower edge; minor foxing. Atlas comprising 11 large maps, including the rare topographical map extending from Lake Tahoe to Mud Flat, Horse Lake and the area above Pyramid Lake. Shows towns, roads, mountains, rivers, lakes, hydrographical details, etc. Tmap was prepared during the Wheeler Survey. The Wheeler Survey was a survey of a portion of the United States lying west of the 100th meridian. It comprised multiple expeditions and was supervised by First Lieutenant (later Captain) George Montague Wheeler. The survey team included Lieutenant (later Brigadier General) Montgomery M. Macomb. Wheeler led early expeditions from 1869 to 1871 in the west, and in 1872, the US Congress authorized an ambitious plan to map the portion of the United States west of the 100th meridian at a scale of 8 miles to the inch. This plan necessitated the Wheeler Survey. The survey's main goal was to make topographic maps of the southwestern United States. In addition, Wheeler's survey was undertaken to ascertain everything related to the physical features of the region; discover the numbers, habits, and disposition of Indians in the section; select sites for future military installations; determine facilities available for making rail or common roads; and note mineral resources, climate, geology, vegetation, water sources, and agricultural potential. The Wheeler Survey lasted until 1879, when the survey, along with the King and Powell Surveys, were terminated and their work was reorganized as the United States Geological Survey.