- Byers Engineering Co
- C A Simon & Assoc Inc
- C A Simon & Assoc Inc
- Catro Inc
- Diversified Engineers-Amer
- East Texas Technology LP
- East Texas Technology LP
- Eleven Trees Engineering
- Eleven Trees Engineering
- ENI
- ENI
- Hatfield & Dawson Consulting
- Ladd Engineering Assoc Inc
- Mid-State Consultants Inc
- Pivotal Communications
- Retcom Inc
- Rocky Mountain West Telcom
- Rocky Mountain West Telcom
- Salbu Research & Development
- Trott Communications Group
