Post Offices List in McCook County, South Dakota:
| Bridgewater Post Office | 235 N Main Ave, Bridgewater, SD 57319 |
| Canistota Post Office | 222 W Main St, Canistota, SD 57012 |
| Montrose Post Office | 105 W Main St, Montrose, SD 57048 |
| Salem Post Office | 311 N Main St, Salem, SD 57058 |
| Spencer Post Office | 306 Main St, Spencer, SD 57374 |