| Business | Phone |
| Benton County Commissioners 620 Market St, Prosser 99350 | (509) 786-5600 |
| Benton County Cooperative Ext 1121 Dudley Ave, Prosser 99350 | (509) 786-5609 |
| Benton County Elections 620 Market St, Prosser 99350 | (509) 786-5618 |
| Benton County Noxious Weed Brd 1215 Dudley Ave, Prosser 99350 | (509) 786-6988 |
| Benton County Personnel Dept Courthouse, Prosser 99350 | (509) 736-3081 |
| Benton County Planning Dept 1002 Dudley Ave, Prosser 99350 | (509) 736-3086 |
| Benton County Recording 620 Market St, Prosser 99350 | (509) 786-5616 |
| Benton Maintenance 14303 N Hinzerling Rd, Prosser 99350 | (509) 786-4810 |
| Benton Planning Dept 1002 Dudley Ave, Prosser 99350 | (509) 786-5612 |
| Board Of Equalization Courthouse, Prosser 99350 | (509) 786-5604 |