Phone numbers in Clark, South Dakota
Clark has 3 phone prefixes in area code 605.
Biggest holders: AT&T Mobility, Interstate Telecom Coop. This is the local calling area (rate center) where those prefixes were first assigned.
- Mobile carrier 67%
- Phone company 33%
Every prefix in Clark
Search the first six digits of a number in this list. If it's here, the number started in Clark with the carrier shown. If it isn't, check the South Dakota page or look the number up.
| Prefix | Carrier | Type | Assigned |
|---|---|---|---|
| 605-233 | AT&T Mobility | Mobile carrier | 2003 |
| 605-532 | Interstate Telecom Coop | Phone company | – |
| 605-844 | AT&T Mobility | Mobile carrier | 2010 |
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.