| Business | Phone |
| American Postal Workers Union 530 S 27th St, Billings 59101 | (406) 259-9930 |
| American Postal Workers Union 841 S 26th St, Billings 59101 | (406) 896-9242 |
| Teamsters Union 437 Kuhlman Dr, Billings 59105 | (406) 248-2658 |
| Carpenters Union 530 S 27th St, Billings 59101 | (406) 259-6911 |
| Oil Chemical & Atomic Workers 108 11th St W, Billings 59102 | (406) 252-7575 |
| Operating Engineers 530 S 27th St, Billings 59101 | (406) 252-7966 |
| Painters 530 S 27th St, Billings 59101 | (406) 252-2535 |
| Plumbers & Pipefitters Union 317 Washington St, Billings 59101 | (406) 252-9371 |
| Montana Public Employees Assn 2914 Springfield Ave, Billings 59101 | (406) 896-0734 |
| Ibew 5200 Midland Rd, Billings 59101 | (406) 248-9119 |
| Mail Handlers Union 530 S 27th St, Billings 59101 | (406) 248-9142 |
| Laborers Local 1111 Main St # 9, Billings 59105 | (406) 259-4471 |