Resident Population in Lake County, CA was 67.76400 Thous. of Persons in January of 2024, according to the United States Federal Reserve. Historically, Resident Population in Lake County, CA reached a record high of 68.62300 in January of 2021 and a record low of 19.54800 in January of 1970. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Lake County, CA - last updated from the United States Federal Reserve on April of 2026.