Little Bighorn River Bighorns have rattlesnakes because they also support a habitat for small mammals, like a mouse and chipmunk population, which are the prey of rattlesnakes. With the restoration of the black bear population in the Bighorn Mountains, there has been a resurgence of black bear living along the stream as it flows out of Montana, extending down the Little Bighorn Valley in Montana. Ranchers between the mouth of the canyon (at about the Wyoming Montana line) down to Wyola often report black bear groups living in the timber along the river, and travelers on the Montana portion of the Little Horn
Little Bighorn River led a government expedition up the Big Horn River to the mouth of Big Horn Canyon, and then southeast along the base of the Big Horn mountains. En route to the Big Horn Canyon, and about 40 miles down the Big Horn River, he camped just below the mouth of the Little Bighorn on September 6, 1859. He noted in his journal for that day that the Indian name of the Big Horn river, into which the Little Bighorn empties, is "Ets-pot-agie", or Mountain Sheep River, and this generates the name of the Little Big Horn, "Ets-pot-agie-cate", or Little Mountain