Reference Data Rate Center Directory JEFFERSON, SD Rate Center JEFFERSON — SD Data last updated: March 10, 2026 LATA 640 State SD Area Codes 1 Exchanges (NXX) 1 Carriers 1 Coordinates 42.60257317882319, -96.56080305229264 Area Codes 605 Top Carriers Carrier OCN NXX Count JEFFERSON TEL. CO. 1666 1
