| Business | Phone |
| Maintenance Garage West 708 20th St, Onawa 51040 | (712) 433-2635 |
| Monona County Assessor's Ofc 610 Iowa Ave, Onawa 51040 | (712) 433-2271 |
| Monona County Auto Dept 610 Iowa Ave, Onawa 51040 | (712) 433-2702 |
| Monona County Engineer 610 Iowa Ave, Onawa 51040 | (712) 433-2284 |
| Monona County Extension Svc 119 Iowa Ave, Onawa 51040 | (712) 423-2175 |
| Monona County Recorder 610 Iowa Ave, Onawa 51040 | (712) 433-2575 |
| Monona County Relief 909 7th St, Onawa 51040 | (712) 423-1921 |
| Monona County Veteran Affairs 610 Iowa Ave, Onawa 51040 | (712) 433-3710 |
| Monona Dist Judicial Chambers 610 Iowa Ave, Onawa 51040 | (712) 423-2167 |
| Monona County Drainage Clerk 610 Iowa Ave, Onawa 51040 | (712) 433-2630 |