The short report was written primarily to explain the important map, drawn by Charles Preuss, which covers the entire West from the Rockies to the Pacific, measuring 83x66 cm., with a little hand coloring in outline. Wheat calls the map "the one great general map of 1848." He also comments that it is probably the first map, with a wide circulation, to locate the gold regions in California. The report of this third expedition of Fremont is uncharacteristically short, due to Fremont's court martial and resignation from military service. Nevertheless, it enjoyed great popularity since the discovery of gold was announced almost simultaneously with its publication. Cowan p.233; Graff 1429; Sabin 25837; Howes F366; Kurutz 256b; Wagner-Camp 150:2; Wheat Gold Region 58; Wheat Transmississippi 559.