| Business | Phone |
| Center Point Energy 109 Nw 50th St, Oklahoma City 73118 | (405) 556-2400 |
| Enogex Inc 420 S Broadway Ave, Oklahoma City 73109 | (405) 557-7900 |
| Interstate Gas Svc Inc 5400 N Grand Blvd, Oklahoma City 73112 | (405) 917-7700 |
| Medical Gas Management Inc 5801 Phillip J Rhoads Ave, Oklahoma City 73122 | (405) 787-1134 |
| Oklahoma Natural Gas Co 401 N Harvey Ave, Oklahoma City 73102 | (405) 551-4000 |