This lot contains two maps issued in Report Upon the Reconnaissance of Northwestern Wyoming, Made in the Summer of 1873:

A. Geological Map of Western Wyoming Illustrating the Report of Mr. Theo. B. Comstock..., printed color. A handsome and colorful map that illustrated the report of T.B. Comstock, the geologist to the Military Reconnaissance of the region that was conducted by Capt. W.A. Jones, Corps of Engineers. This is one of the earliest geological maps of Yellowstone country based on actual exploration, preceded only by Hayden's very rare separately published Snake River and Montana, and Wyoming Territories maps (Marcou & Marcou 629 & 630). Chart shows geological types, the topography and trails in the northwestern part of Wyoming, including roads, stage stations, military posts, astronomical observation stations and boundaries of the Snake Indian Reservation. Area includes Jackson Hole, the Big Horn and Teton Mountains, and extends south to Fort Bridger and the Sweetwater Mountains. Terrific detail of the newly formed Yellowstone Park. Condition: Light toning and color offsetting, and a small chip at bottom right with minor loss of border. (B)

B. Map of a Military Reconnoissance, in North Western Wyoming..., black & white. This is the same base topographical map as above. Includes an inset at lower left that shows the expedition trail extending into Montana (the geological map covers this up with a key). Condition: Light toning along the fold lines. (B+)

References: Marcou & Marcou #631; Blevins Mapping Wyoming #256.

Condition:

Issued folding and now flattened and backed with tissue. See description above.