| Business | Phone |
| Frear Consulting 113 S Gillette Ave, Gillette 82716 | (307) 682-3100 |
| Hollingsworth Associates 305 Commerce Dr 9d, Gillette 82718 | (307) 686-7669 |
| Applied Hydrology Intl 612 N Us Highway 14-16, Gillette 82716 | (307) 685-3044 |
| Kadrmas Lee & Jackson 801 E 4th St 22, Gillette 82716 | (307) 682-9500 |