Resident Population in Prairie County, MT was 1.11200 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Prairie County, MT reached a record high of 1.90000 in January of 1978 and a record low of 1.05400 in January of 2007. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Prairie County, MT - last updated from the United States Federal Reserve on May of 2024.