Mountrail County is a county in the northwestern part of North Dakota, United States. As of the 2020 census, the population was 9,809. Its county seat is Stanley. The county was originally created in 1873, then removed in 1892, annexed by Ward County. It was re-created and organized in 1909.

Ward County is a county in the U.S. state of North Dakota. As of the 2020 census, the population was 69,919, making it the fourth most populous county in North Dakota. Its county seat is Minot. Ward County is part of the Minot, ND Micropolitan Statistical Area.