| Business | Phone |
| Ontonagon Housing Commission 100 Cane Ct, Ontonagon 49953 | (906) 884-2258 |
| Municipal Garage 901 River St, Ontonagon 49953 | (906) 884-4870 |
| Ontonagon County Juvenile Ofcr 725 Greenland Rd, Ontonagon 49953 | (906) 884-4539 |
| Business Office 315 Quartz St, Ontonagon 49953 | (906) 884-2305 |
| Ontonagon County Road Comm 415 Spar St, Ontonagon 49953 | (906) 884-2332 |
| Ontonagon County Accounting 725 Greenland Rd, Ontonagon 49953 | (906) 884-4257 |
| Ontonagon Twp Clerk 311 N Steel St, Ontonagon 49953 | (906) 884-2415 |
| Storage Garage Rockland Rd, Ontonagon 49953 | (906) 884-4650 |
| Michigan State University Ext 725 Greenland Rd, Ontonagon 49953 | (906) 884-4386 |
| Ontonagon County Title Office 15 S 4th St, Ontonagon 49953 | (906) 884-4375 |
| Stock Room 415 Spar St, Ontonagon 49953 | (906) 884-2399 |