W.R. Reynolds was directed to explore the extensive and then relatively unknown country drained by the Upper Missouri and Yellowstone Rivers. Dr. F. V. Hayden (who later led the expedition that resulted in Yellowstone National Park being established in 1872) accompanied the expedition as a scientist and Jim Bridger acted as guide. Only snowfall prevented Reynolds from being the first non-Indian to see the thermal regions of the Yellowstone National Park. Wheat considered it a very well drawn map and possible the best map of the area that had been produced at that time.

References: Wheat (TMW) 1012.

Condition: B

Evenly toned, a little more so along a couple folds. Issued folded, now backed with archival tissue.