The Beaverhead–Deerlodge National Forest, Montana's largest, encompasses a vast 3.36 million acres across eight counties in the southwestern part of the state. Its origins trace back to President Theodore Roosevelt's 1908 legislation, where he created the Deerlodge National Forest (then Big Hole Forest Reserve) to protect an area ravaged by clearcutting and pollution from the Anaconda Copper Mining Company; the two forests officially merged in 1996. This expansive wilderness hosts significant mountain ranges and the Anaconda-Pintler Wilderness, providing diverse habitats for wildlife such as grizzly bears, gray wolves, and bald eagles. A key historical landmark, Lemhi Pass—designated in 1960—is where the Lewis and Clark Expedition first glimpsed the headwaters of the Columbia River in 1805, marking a pivotal moment in their journey. With over 1,500 miles of hiking trails and 50 campgrounds, the forest offers extensive recreational opportunities amidst its majestic landscapes.