Resident Population in Adams County, ID was 4.99800 Thous. of Persons in January of 2024, according to the United States Federal Reserve. Historically, Resident Population in Adams County, ID reached a record high of 4.99800 in January of 2024 and a record low of 2.87700 in January of 1970. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Adams County, ID - last updated from the United States Federal Reserve on April of 2026.