Washington, D. C.: Printed by Order of the Senate, by Gales and Seaton, 1845. First edition. 8vo. Large map folding on linen in pocket at rear (spotting); 4 lithographed maps (2 folding); 22 lithographed plates. (Offsetting and toning throughout, few small cellotape repairs to title-page verso.) Later cloth; stamp of Library of the U.S. Geological Survey; book-plate of The Peter Kalm Library of Geology, Upsala College. Graff 1436; Howes F-370; Sabin 25845; Streeter VI:3131; Wagner-Camp 115:1.

First edition, the Senate issue, with the astronomical and meteorological observations omitted from the House issue and subsequent editions. The two reports, written with the help of Fremont's wife Jessie Benton, "caught the public imagination: images of Fremont's guide, the then little-known Christopher 'Kit' Carson, riding bareback across the prairie, and Fremont himself, raising a flag on a Rocky Mountain peak, entered the national mythology" (Pamela Herr, ANB).