| Business | Phone |
| American Postal Workers Union 2901 Murphy Dr, Sioux City 51111 | (712) 258-5633 |
| Asbestos Workers Local 1481 140th St, Sioux City 51106 | (712) 258-0145 |
| Carpenters Union 321 5th St, Sioux City 51101 | (712) 255-1567 |
| Communications Workers-America 1325 Lewis Blvd, Sioux City 51105 | (712) 252-1308 |
| Ibew 5001 Harbor Dr, Sioux City 51111 | (712) 255-8138 |
| International Assoc-Machinists 1720 W 1st St, Sioux City 51103 | (712) 255-8387 |
| Northwest Iowa Labor Council 3038 S Lakeport St, Sioux City 51106 | (712) 276-0473 |
| Operating Engineers 234 321 5th St, Sioux City 51101 | (712) 255-1374 |
| Painters' Local 214 507 7th St 319, Sioux City 51101 | (712) 252-2806 |
| Plumbers & Steamfitters 33 1012 W 7th St, Sioux City 51103 | (712) 234-1688 |
| United Food & Commercial Wrkrs 3038 S Lakeport St, Sioux City 51106 | (712) 276-8510 |
| United Food Workers 1142 705 Douglas St 250, Sioux City 51101 | (712) 255-4726 |
| Workers Have Rights Too 211 4th St, Sioux City 51101 | (712) 293-1025 |