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 map noteworthy for it use of the contour system. The inset map "Sketch of Rio Pecos at Anton Chico" is the first map of this type to use the contour system. The map features a long list of authorities used for topography not covered by this survey. Wheat considers this list important as it gives all the surveys that had gone before it in the period 1846-1853. The map has excellent detail along the route that follows the Canadian River then up Pajarito Creek and over the mountains near Albuquerque. Locates forts, mounds, trading posts, the Santa Fe Trail, Raton Pass, Taos and Santa Fe.

References: Wheat (TMW) #874.

Condition: B

Toned along fold lines. Issued folding, now backed with tissue with a deep crease along one fold, mostly in blank area.