The era of continental expansion culminated with the Oregon Treaty of 1846 and the conclusion of the Mexican-American War in 1848 and was closely followed by the discovery of gold in California. Thus began a period of rapid exploration and growth in this huge region. Mitchell’s series of maps of the American West, published between 1846 and 1859, provide a fascinating view of the rapidly changing region.

This version was re-engraved on the same plate as the previous edition, with a new title and several notable updates. This is the first edition of this title showing counties in California and New Mexico. Oregon Territory takes in all of present-day Washington and Idaho with the eastern boundary abutting Missouri Territory. Lewis & Clark’s route and the Oregon Trail are shown. The huge and newly formed Utah Territory covers the region labeled Fremont Basin and stretches from the California border to just past the Rocky Mountains. The Owens Valley, Humboldt, and Nicollet lakes are present, and Fremont’s route from Walker Lake to Salt Lake is shown. The tributaries of the upper Colorado River are updated, adding the White River, Red River, etc. New Mexico Territory (also formed in 1850) encompasses parts of present-day Colorado and Arizona with its southern boundary on the Gila River in a pre-Gadsden Purchase configuration. The Gila River is shown correctly with its terminus in the Colorado River. Published in 1852.

References: Rumsey #0553.001; Wheat (TMW) #754; Wheat (Gold) #225.

Condition: B+

Contemporary color on a lightly toned sheet.