How many acres is the Horse Range that was established by Congress in Bighorn Canyon National Recreation Area?
Bighorn Canyon National Recreation Area: Bighorn Canyon National Recreation Area is a national park unit established by an act of Congress on October 15, 1966, following the construction of the Yellowtail Dam by the Bureau of Reclamation. Pryor Mountains Wild Horse Range:  The range has an area of 39650 acre and was established in 1968 along the Montana–Wyoming border as the first protected refuge dedicated exclusively for Mustangs.
39650 acre