Resident Population in Lewis County, ID was 3.73900 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Lewis County, ID reached a record high of 4.40000 in January of 1978 and a record low of 3.46800 in January of 1987. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Lewis County, ID - last updated from the United States Federal Reserve on May of 2024.