Resident Population in Marshall County, OK was 15.97000 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Marshall County, OK reached a record high of 16.94600 in January of 2019 and a record low of 7.68200 in January of 1970. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Marshall County, OK - last updated from the United States Federal Reserve on May of 2024.