| Business | Phone |
| Unifield Engineering Inc 2626 Lillian Ave, Billings 59101 | (406) 245-4455 |
| Bison Engineering Inc 1411 4th Ave N, Billings 59101 | (406) 896-1716 |
| Retec Group Inc 2048 Overland Ave # 101, Billings 59102 | (406) 652-7481 |
| Olympus Technical Svc Inc 547 S 20th St W # 5, Billings 59102 | (406) 245-3554 |
| Maxim Technologies Inc 618 S 25th St, Billings 59101 | (406) 248-9161 |