Reference Data Rate Center Directory GANNVALLEY, SD Rate Center GANNVALLEY — SD Data last updated: March 10, 2026 LATA 640 State SD Area Codes 1 Exchanges (NXX) 1 Carriers 1 Coordinates 44.03255810490373, -98.98835555918824 Area Codes 605 Top Carriers Carrier OCN NXX Count MIDSTATE COMMUNICATIONS, INC. 1670 1
