"580" . . "-5" . "73039 (historically), 73434 (today)" . "Foster is a town in Garvin County, Oklahoma, United States. It was incorporated in 2002 and had an estimated population of 124 in 2007.Foster is served by State Highway 29A, a spur of State Highway 29. A post office was first established at Foster on August 12, 1891."@en . "-6" . . "Foster, Oklahoma"@en . . . . "297.0"^^ . "296.875"^^ .