It is the last habitat in the contiguous United States for native fluvial Arctic grayling[4] and is a historically popular destination for fly fishing, especially for trout.

At the time the Lewis and Clark Expedition traveled through the Big Hole River watershed, it was a buffer zone between several rival Native American tribes including the Nez Percé, Shoshone, Coast Salish, and Blackfeet.

[6] The establishment of Butte, Montana as a mining center and the coming of the Northern Railroad in 1871 assured Big Hole ranchers and farmers of a steady market for their beef, horses, mules, hay and dairy products.

[7] As a great improvement for preserving the wild hay for winter feeding of cattle, Herbert S. Armitage and David J. Stephens filed for a "Hay-Stacker" patent in 1909, which was awarded in 1910.

Conservationist George F. Grant, Trout Unlimited and local ranchers combined forces to oppose the dam, successfully defeating the proposal in 1967.

Fluvial Arctic grayling lived historically in the United States only in Michigan and the upper Missouri River above Great Falls, Montana.

The Watershed Committee reached out to local and selected interested entities and developed a viable community-based consensus group to forge solutions to difficult problems that impact the river.

An Office of the Inspector General investigation found that "MacDonald has been heavily involved with editing, commenting on, and reshaping the Endangered Species Program's scientific reports."

Instead, the river holds healthy wild populations of brook, rainbow and brown trout which were first introduced into the Big Hole in late 1880s as hatchery operations began in Butte and Bozeman, Montana.