Resident Population in Iosco County, MI was 25.26600 Thous. of Persons in January of 2025, according to the United States Federal Reserve. Historically, Resident Population in Iosco County, MI reached a record high of 31.12000 in January of 1991 and a record low of 24.44000 in January of 1994. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Iosco County, MI - last updated from the United States Federal Reserve on June of 2026.