Little Bighorn River Canyon trail was originally established for the purposes of delivering mail to Bald Mountain City, a gold mining town, in the late 1800s. The trail is now primarily used by cattle ranchers, marathon runners, and fisherman. After flowing out of Wyoming and into Montana at the mouth of Little Bighorn Canyon, the entire remaining course of the Little Bighorn River and all its tributaries are within the boundaries of the Crow Indian Reservation, and access to the river is subject to the unique and confusing mixture of Montana state and Crow tribal law. Fishing within the boundaries of the Crow
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