Reference Data Rate Center Directory MOUND CITY, SD Rate Center MOUND CITY — SD Data last updated: March 10, 2026 LATA 640 State SD Area Codes 1 Exchanges (NXX) 1 Carriers 1 Coordinates 45.72571929512623, -100.0694037343933 Area Codes 605 Top Carriers Carrier OCN NXX Count VALLEY TELECOM COOP. ASSN., INC. 1685 1
