Resident Population in Carter County, MT was 1.41800 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Carter County, MT reached a record high of 1.95600 in January of 1970 and a record low of 1.13600 in January of 2011. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Carter County, MT - last updated from the United States Federal Reserve on May of 2024.