"Gray Horse (Pawnee: K\u00FArahkaac ) is a small unincorporated community in Osage County, Oklahoma. The post office was established May 5, 1890, and discontinued December 31, 1931. It was named for Gray Horse (Ko-wah-hos-tsa), an Osage medicine man."@en . . . "Gray Horse"@en . . "-5" . . . "-6" .