(West - ID.-MT.) Amer. Sep. Partie Des Etats-Unis. No. 39.
A early map to focus on this region of the northern Rockies, covering portions of modern Idaho and western Montana. Illuminates the major terrain and drainages, with some notations for major peaks. Notes numerous tribes with estimates of their population. Amazing work for the time, when the region was still part of a vast unincorporated Northwest Territory (Missouri Territory).
Condition is good with minor centerfold repair and margins trimmed very closely. Image size is approximately 18.75 x 20.75 (inches)