Resident Population in Mountrail County, ND was 9.38300 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Mountrail County, ND reached a record high of 10.50700 in January of 2019 and a record low of 6.37600 in January of 2006. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Mountrail County, ND - last updated from the United States Federal Reserve on May of 2024.