Reference Data Rate Center Directory CALLAO, MO Rate Center CALLAO — MO Data last updated: March 10, 2026 LATA 524 State MO Area Codes 1 Exchanges (NXX) 1 Carriers 1 Coordinates 39.76086470000001, -92.6232452 Area Codes 660 Top Carriers Carrier OCN NXX Count CHARITON VALLEY TEL. CO. 1864 1