| Business | Phone |
| Chamberlain City Engineer 715 N Main St, Chamberlain 57325 | (605) 734-4400 |
| Chamberlain Finance Office 715 N Main St, Chamberlain 57325 | (605) 734-4401 |
| Chamberlain Wastewater Sewer River St, Chamberlain 57325 | (605) 734-4411 |
| Oacoma City Finance Office 108 S Main St, Chamberlain 57325 | (605) 734-4455 |