Oklahoma County, Oklahoma Oklahoma County, Oklahoma Oklahoma County is a county located in the central part of the U.S. state of Oklahoma. As of the 2010 census, the population was 718,633, making it the most populous county in Oklahoma. The county seat is Oklahoma City, the state capital. Oklahoma County is at the heart of the Oklahoma City Metropolitan Statistical Area. Oklahoma County is one of seven counties in the United States to share the same name as the state it is located in (the other six counties are Arkansas County, Hawaii County, Idaho County, Iowa County, New York County (known commonly as
Oklahoma State Highway 99 become a U.S. Route, while another suggested a northern terminus at US-64 near Cleveland. On June 18, 1964, AASHTO accepted an extension of US-377 from Texas to US-70 in Madill. The Department of Highways, and later the Department of Transportation, submitted an application to extend US-377 from Madill to US-64 in Cleveland eight times between December 1964 and 1980. In 1991, ODOT signed the route to Stroud along SH-99 without AASHTO approval. SH-99 has two lettered spurs: Oklahoma State Highway 99 State Highway 99, abbreviated SH-99, is a north–south state highway through central Oklahoma. It runs from the Texas border