Reference Data Rate Center Directory HERREID, SD Rate Center HERREID — SD Data last updated: March 10, 2026 LATA 640 State SD Area Codes 1 Exchanges (NXX) 1 Carriers 1 Coordinates 45.83562480943444, -100.0698985031944 Area Codes 605 Top Carriers Carrier OCN NXX Count VALLEY TELECOM COOP. ASSN., INC. 1685 1
