583pp. Illus. with 22 lithograph plates; 5 maps, 3 of them folding, including the very large one at rear. (8vo) 8¾x5½, period half calf and marbled boards, rebacked with original spine laid down. First Edition, House Issue.

The first portion of the work reprints Fremont's report of 1843, covering his 1842 expedition to the Rocky Mountains, the second portion records his expedition of 1843-1844, delineating the major sections of the route subsequently followed by thousands of Oregon immigrants. Wheat describes the map at great length, and attaches great importance to it: "The year 1845, however, though otherwise somewhat cartographically barren, because of a single event is in fact one of the towering years in the story of Western Cartography. In that year John C. Fremont's report of his journey to Oregon and California in 1843-44 was published. This report and the Fremont (Preuss) map which accompanied it, changed the entire picture of the West, and made a lasting contribution to cartography..." The map is somewhat darkened, small tears at the folds, as usual, stain in the Pacific Ocean portion. Cowan p. 223-4; Graff 1436; Howes F370; Wagner-Camp 115:2; Wheat Transmississippi Vol. II, pp. 194-200, Map 497; Zamorano 39.