Resident Population in Rooks County, KS was 4.74800 Thous. of Persons in January of 2024, according to the United States Federal Reserve. Historically, Resident Population in Rooks County, KS reached a record high of 7.62800 in January of 1970 and a record low of 4.74800 in January of 2024. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Rooks County, KS - last updated from the United States Federal Reserve on April of 2026.