Resident Population in Deer Lodge County, MT was 9.81100 Thous. of Persons in January of 2024, according to the United States Federal Reserve. Historically, Resident Population in Deer Lodge County, MT reached a record high of 15.90000 in January of 1972 and a record low of 8.72900 in January of 2009. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Deer Lodge County, MT - last updated from the United States Federal Reserve on April of 2026.