| Business | Phone |
| West Plains Engineering Inc 1750 Rand Rd, Rapid City 57702 | (605) 348-7455 |
| Skyline Engineering 615 12th St, Rapid City 57701 | (605) 737-3800 |
| Fiberswitch Technologies 1739 W Main St, Rapid City 57702 | (605) 341-8865 |
| Phil Nichols Assoc 11735 W Highway 44, Rapid City 57702 | (605) 343-3986 |