Approximately "fifty miles long and fifteen miles wide," Big Hole Prairie "is hemmed in by high mountains on every side except the southeast where Wisdom River passes out from it." Plate XLIX.
Expeditions & surveys; Railroad surveys; Palouse River (Wash.); Mountains
The Peluse (Palouse) River "has its source in the main ridge of the Bitter Root" Mountains, "and flows in nearly a straight course through a valley some twenty miles wide," bearing north "through a country densely timbered...
"This valley for the most part is wide and open." There are "spurs separating it from the Hell-Gate Valley on the south," and "separate on the north the various tributaries flowing into the Blackfoot River." Plate LXII.