During the 1850s, the U.S. government sponsored an extensive series of expeditions designed to gather information on the vast new territories that had been acquired in western North America. The discovery of gold in California further stimulated westward traffic and heightened the need for a faster and more convenient way to bring the far-flung parts of the country together. In 1853 Congress commissioned the Army's Topographic Bureau to conduct a series of surveys to find a suitable route for a transcontinental railroad. There were six major expeditions; five of them covered the area between the Great Plains and west coast, and the sixth explored the coastal states of California and Oregon. All of these expeditions were accompanied by naturalists and artists to document the landscape, flora and fauna along the route. The reports, maps and lithographs were published in the 13 volume report "Explorations and Surveys to ascertain the most practicable and economical route for a Railroad from the Mississippi river to the Pacific Ocean."

Wheat calls this "one of the best maps" drawn by F.W. Egloffstein on these surveys. It stretches from the southern fork of the Humboldt River west to Pyramid Lake, which is passed to the north by the proposed railroad route. The map is filled with topographical detail including fine hachure. An area to the north is noted as Unexplored.

References: Wheat (TMW) #824.

Condition: B+

Issued folding, now flat and backed with archival tissue to repair a couple separations and a split at the fold junction. There is minor toning along the folds and a binding trim at bottom left that has been replaced with paper.