Reference Data Rate Center Directory KEYSTONE, OK Rate Center KEYSTONE — OK Data last updated: March 10, 2026 LATA 538 State OK Area Codes 1 Exchanges (NXX) 1 Carriers 1 Coordinates 36.19941282867391, -96.29683708784778 Area Codes 918 Top Carriers Carrier OCN NXX Count CIMARRON TEL. CO. 1982 1
