Resident Population in Dewey County, OK was 4.28600 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Dewey County, OK reached a record high of 6.71100 in January of 1983 and a record low of 4.28600 in January of 2023. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Dewey County, OK - last updated from the United States Federal Reserve on May of 2024.