Eagle City is a small rural community located along and west of State Highway 58 in western Blaine County, Oklahoma, United States. Established on the Frisco Line before statehood, the post office which opened July 26, 1902 was named Dillon. The name was changed to Eagle City September 4, 1909. The ZIP Code is 73658. The nearest post of…Eagle City is a small rural community located along and west of State Highway 58 in western Blaine County, Oklahoma, United States. Established on the Frisco Line before statehood, the post office which opened July 26, 1902 was named Dillon. The name was changed to Eagle City September 4, 1909. The ZIP Code is 73658. The nearest post office is now in Oakwood.