Resident Population in Valley County, MT was 7.47400 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Valley County, MT reached a record high of 12.80000 in January of 1973 and a record low of 6.76800 in January of 2009. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Valley County, MT - last updated from the United States Federal Reserve on May of 2024.