Musselshell County, Montana: History
Musselshell County was created in 1911 by Montana Governor Edwin L. Norris. The area was taken from Fergus, Yellowstone, and Meagher counties. It was named for the Musselshell River which runs southwest–northeast through the county. That river had been thus named in 1805 by the Lewis and Clark Expedition, due to the abundance of freshwater mussels found along its banks. In 1915, a western portion of the county was partitioned off to form Golden Valley County, giving Musselshell County its present boundaries.
The county's northwestern area is rolling grasslands, which slope southeastward to the Musselshell River and the forested Bull Mountains in the southeast. The county has abundant natural resources of coal deposits, subterranean oil, and timbered slopes.