Resident Population in Isabella County, MI was 64.11800 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Isabella County, MI reached a record high of 71.24700 in January of 2016 and a record low of 44.59400 in January of 1970. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Isabella County, MI - last updated from the United States Federal Reserve on May of 2024.