| Business | Phone |
| Poehlman & Prost Inc 9280 Dielman Industrial Dr, St Louis 63132 | (314) 997-5777 |
| O'Brien & Gere Engineers Inc 12250 Weber Hill Rd, St Louis 63127 | (314) 842-4550 |
| Efk Moen 13523 Barrett Pkwy Dr # 250, St Louis 63131 | (314) 729-4100 |
| Clayton Engineering Co 11920 Westline Industrial Dr, St Louis 63146 | (314) 692-8888 |
| Cmv Engineering 5751 Greenton Way, St Louis 63128 | (314) 487-5354 |
| Diversified Development Desgns 10644 Tioga Ct, St Louis 63128 | (314) 842-2560 |
| Doering Engineering Inc 4850 Lemay Ferry Rd, St Louis 63129 | (314) 487-6913 |