Post Offices List in Dewey County, South Dakota:
| Eagle Butte Post Office | 121 Main St, Eagle Butte, SD 57625 |
| Isabel Post Office | 200 Main St, Isabel, SD 57633 |
| Lantry Post Office | 14 Wheat Ave, Lantry, SD 57636 |
| Ridgeview Post Office | 1 Us Highway 212, Ridgeview, SD 57652 |
| Timber Lake Post Office | 801 Main St, Timber Lake, SD 57656 |
| Trail City Post Office | 130 N Main St, Trail City, SD 57657 |
| Whitehorse Post Office | 18 S 2nd Ave, Whitehorse, SD 57661 |