Musselshell County is named for the Musselshell River which was named by the Lewis and Clark Expedition due to mussels found on the banks of the river.
Surrounding County Courthouses:
N – Fergus County and Petroleum County
E – Rosebud County and Treasure County
Created: February 11, 1911 
County Seat:
Roundup 1911 – present
County Courthouse – Roundup
Location: 506 Main Street / 5th Avenue East
Built: 1939 – 1940
Style: Art Deco
Architect: J G Link of Billings
Contractor: Lovering Construction Company of St. Paul, Minnesota
Description: The building faces west and is a two story dark red colored brick and concrete structure. The building is located on landscaped grounds in the center of Round Up. The west front of the rectangular shaped building has a projecting center section with six vertical concrete pillars with the entrance at the center. The roof line is flat. The building houses the County District Court of the 14th Judicial District and County Justice Court.
See: The architect, John G Link of Montana ( in association with Charles S Haire and others ) designed courthouses in Montana in Big Horn County, Carter County, Custer County, Dawson County, Granite County, McCone County, Richland County, Rosebud County, Sheridan County and Silver Bow County; in Oregon in Jackson County and in Wyoming in Park County, Sheridan County and Washakie County.
See: The 14th Judicial District includes Golden Valley County, Meagher County, Musselshell County and Wheatland County.
History: The county was created in 1911 and Round Up was selected as the county seat. The first courthouse was a two story rectangular structure. The second and present courthouse was constructed in 1939 to 1940.
County Courthouse - Roundup
Commissioner Minutes – contractor
Photos taken 2011