Roundup is a city in and the county seat of Musselshell County, Montana, United States. The population was 1,742 during the 2020 census.
Musselshell County Courthouse
Musselshell County, Montana
Musselshell County is a county in south-central Montana. As of the 2020 census, the population was 4,730. Its county seat is Roundup.
The Musselshell County Courthouse in Roundup