Washington -- U.S. County in Oklahoma Population (2000): 48996 Housing Units (2000): 22250 Land area (2000): 416.815911 sq. miles (1079.548207 sq. km) Water area (2000): 7.338957 sq. miles (19.007811 sq. km) Total area (2000): 424.154868 sq. miles (1098.556018 sq. km) Located within: Oklahoma (OK), FIPS 40 Location: 36.728513 N, 95.938140 W Headwords: Washington Washington, OK Washington County Washington County, OK