Phone numbers in Hill City, South Dakota
Hill City has 4 phone prefixes in area code 605.
Biggest holders: Airus, CenturyLink / Lumen, T-Mobile (including Sprint). This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 25%
- Local phone company 25%
- Internet / business phone carrier 25%
- Phone company 25%
Every prefix in Hill City
Search the first six digits of a number in this list. If it's here, the number started in Hill City with the carrier shown. If it isn't, check the South Dakota page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 605-307 | Airus | Phone company | 2019 |
| 605-574 | CenturyLink / Lumen | Local phone company | – |
| 605-617 | T-Mobile (including Sprint) | Mobile carrier | 2026 |
| 605-909 | TON80 Communications | Internet / business phone carrier | 2022 |
Most prefixes are pooled: the 10,000 numbers in each are handed out in blocks of 1,000 to different carriers, and people can also take their numbers to another carrier. So the carrier shown is where the prefix started, not a guarantee about any one number. Source: NANPA central office code records, 2026-10-10.