Report of the Exploring Expedition from Santa Fe, New Mexico, to the Junction of the Grand and Green Rivers of the Great Colorado of the West, in 1859, Under Command of Captain J.N. Macomb with Geological Report By Professor J.S. Newberry, Geologist.

4to., (12 x 9 ½ inches). Large folding lithographic map of "Explorations and Surveys in New Mexico and Utah. 1860" (slightly toned), 11 fine chromolithographic and 11 lithographic plates. Contemporary brown cloth, spine gilt (extremities a bit worn). Provenance: With the contemporary manuscript ownership inscription of "E. Z. Steeven, 1st Lieut. & Adjutant 3rd Cavalry." First edition. Publication of this report was originally intended for 1861, but the Civil War intervened and prevented publication for another fifteen years. The expedition under Macomb went west from Santa Fe across northern New Mexico and Arizona to the Colorado and "showed conclusively that no feasible supply route existed leading into the Great Basin from that direction. However, in the realm of geography and geology its implications were considerable. The whole drainage of the San Juan had been traced and the relationship of that river with the Colorado clearly established. More important, they had also established that the Green River united with the Grand to form the Colorado. The entire maze of intricate canyon country had been threaded, and its geography revealed for the first time. In addition, Newberry was able to establish numerous stratigraphic columns, and to trace the Triassic, Jurassic, and Carboniferous strata far out across the Colorado River. Newberry introduced a new level of sophistication into the study of western geology. Of Newberry it might be said that more than any other scientist since Frémont he had opened up new and unknown country to the civilized world" (Goetzmann, "Army Exploration in the American West"). Alliot, p. 144. Graff 2647. Howes M179.…