Valley County is a county in the U.S. state of Montana. Valley County was created in 1893 with area partitioned from Dawson County. As of the 2020 census, the population was 7,578. Its county seat is Glasgow. It is located on the Canada–United States border with Saskatchewan.

Dawson County is a county located in the U.S. state of Montana. As of the 2020 census, the population was 8,940. Its county seat is Glendive.