Important map of the West, first issued to accompany Charles Wilkes report of the US Exploring Expedition West of the Rocky Mountains, 1841-45. The map extends from Klameth Lake and the Mexican Border in the West to the Anahuac Mountains and the sources of the Green River and Colorado River in the East. This map was originally issued in a larger format and was later reissued in both a small format to accompany the official report and later in a Wilkes production which was issued during the Gold Rush. Incorporates the discoveries of Wilkes, Fremont and others. Wheat 458.