Lewis and Clark National Forest is located in west central Montana, United States. Spanning 2,912 square miles (7,500 km2), the forest is managed as two separate zones. The eastern sections, under the Jefferson Division, is a mixture of grass and shrublands dotted with "island" pockets of forested areas. Here, cattle leases to local ranchers as well as timber harvesting are the norm. The western Rocky Mountain Division, which straddles the Continental divide, is managed chiefly for environmental preservation, as much of the land has been designated as wilderness. Forest headquarters are located in Great Falls, Montana. Local ranger district offices have been established in Choteau, Harlowton, Neihart, Stanford, and White Sulphur Springs.

Lewis and Clark County is a county located in the U.S. state of Montana. As of the 2020 census, the population was 70,973. Its county seat is Helena, the state capital. The numerical designation for Lewis and Clark County is 5. The county was established on June 2, 1865, as one of the nine original counties of the Territory of Montana named Edgerton County in honor of Sidney Edgerton, first Governor of the Territory of Montana, and was renamed Lewis and Clark County on March 1, 1868, in honor of explorers Meriwether Lewis and William Clark.