The forest area comprises a total of with around located in the Gallatin Forest area and within the Custer. Most of the Gallatin borders Yellowstone National Park and is a part of the Greater Yellowstone Ecosystem, an area which encompasses almost in and around the park. The Custer National Forest is spread out along Eastern Montana and the North-West side of Wyoming, with most of its land being held in Montana. The forest stretches through about six counties, including Park, Gallatin, Sweet Grass, Madison, Carbon, and Meagher.
