Frontier City is a western-themed amusement park in Oklahoma City. It is owned by EPR and operated by Six Flags. The park originally opened in 1958. Frontier City is one of three Six Flags parks that are not currently branded as a Six Flags park, with Great Escape in Queensbury, New York and La Ronde in Montreal, Quebec, Canada being the other two. Frontier City is the second-oldest Six Flags park behind Six Flags New England.