| Business | Phone |
| Cranmer Engineering Inc 1188 E Main St, Grass Valley 95945 | (530) 273-7284 |
| King Engineering Inc 10563 Brunswick Rd # 11, Grass Valley 95945 | (530) 272-8328 |
| Lincoln & Long 568 E Main St # D, Grass Valley 95945 | (530) 273-0503 |
| S & E Engineering 10140 Manor Dr, Grass Valley 95945 | (530) 272-7886 |
| Sco Planning & Engineering 140 Litton Dr # 240, Grass Valley 95945 | (530) 272-5841 |
| Summit Engineering Grass Valley 95945 | (530) 477-9034 |
| Counihan Consulting 10986 Rough And Ready Hwy, Grass Valley 95945 | (530) 273-8757 |
| Del Valle Consulting 11768 Tammy Way, Grass Valley 95949 | (530) 272-2500 |
| Lincoln Long 406 E Main St, Grass Valley 95945 | (530) 477-2773 |