Estimate, Median Age by Sex, Total Population (5-year estimate) in Fallon County, MT was 37.20000 Years of Age in January of 2022, according to the United States Federal Reserve. Historically, Estimate, Median Age by Sex, Total Population (5-year estimate) in Fallon County, MT reached a record high of 44.50000 in January of 2009 and a record low of 35.10000 in January of 2021. Trading Economics provides the current actual value, an historical data chart and related indicators for Estimate, Median Age by Sex, Total Population (5-year estimate) in Fallon County, MT - last updated from the United States Federal Reserve on May of 2024.