| Business | Phone |
| Allison Drilling Co Inc 1873 S Bellaire St # 1105, Denver 80222 | (303) 861-2228 |
| Ashby Drilling Corp 518 17th St # 390, Denver 80202 | (720) 359-0718 |
| Camwest Ltd Partnership 1825 Lawrence St, Denver 80202 | (303) 295-6055 |
| Caza Drilling & Exploration Co 1801 Broadway # 360, Denver 80202 | (303) 292-1206 |
| Sst Energy Corp 410 17th St # 1240, Denver 80202 | (303) 595-3212 |
| Patterson-Uti Drilling Co 1600 Broadway, Denver 80202 | (303) 542-1900 |