First Detailed Exploration of the Mojave and Death Valley
In 1871, under the direction of Lt. George M. Wheeler, the U.S. Army Corps of Engineers conducted extensive explorations and surveys in Nevada, Arizona, and California. These efforts, part of the larger Wheeler Survey, aimed to map the vast and largely uncharted territories south of the Central Pacific Railroad. The survey produced detailed topographical maps, including the notable map in the printed report titled "Explorations and Surveys South of Central Pacific R.R." This map and accompanying report provided critical data on the region's geography, geology, and resources, aiding in future development and scientific study of the American West.
According to William Goetzmann: "Wheeler, scarcely thirty years of age, emerged as leader of his own exploration....By dint of two years of hard work in the field, Wheeler became head of an entire bureau of exploration in his own right. And with him he carried the Army's hopes for survival in competition with the able captains of civilian science...What contributed most to Wheeler's sudden success as a Western explorer was his spectacular exploration of 1871. Under orders from General Humphreys, he was sent to explore and map "those portions of the United States territory lying south of the Central Pacific Railroad, embracing parts of Eastern Nevada and Arizona."... In his spare time he was to survey the mineral resources of the country, the geological formations, the vegetation, its suitability for agriculture, the weather, and establish a number of astronomically observed points of latitude and longitude" - Exploration and Empire, page 469-470.
E. I. Edwards includes this report in his bibliography of important works on the California deserts:
These explorations, occurring in 1871, tough upon California desert areas, particularly in and around Death Valley (pp. 15-17, 50-52. 63-64, 83-84). Astronomical aspects of the region are discussed together with the topographical, physico-geographical, meteorological, geological, natural historical, and mineralogical features. Considerable space is devoted to the Indians of the locality, to climate, mines, and agricultural possibilitie. In California mention is made of regions in and about Deep Springs Valley, Fish Spring, Kearsarge, San Carlos, Lone Pine, Coso, Granite Mountain, Telescope Peak, Cottonwood Canyon, Death Valley, and Amargosa Valley. E. P. Austin, G. K. Gilbert, and Lt. D. A. Lyle contribute reports, the latter making reference to the mysterious disappearance of the guide Egan (pp. 83-84).
The large folding map which accompanies the report shows a large swath of the west, including Nevada south of Battle Mountain and Elko, sections of California (Death Valley and as far as San Bernadino) and most of Arizona.