| Alsco - Geyer Irrigation INC | Andy Charles Geyer | — | (530) 476 2253 | Other | Arbuckle · Colusa County | — | — |
| Arrow S Company INC | Lori Michelle Skaggs | — | (707) 396 0073 | Other | Arbuckle · Colusa County | — | — |
| Asa Charles Smith | Asa Charles Smith | — | (530) 330 1900 | Other | Williams · Colusa County | — | — |
| Burgess And Sons Excavating INC | David Marlin Burgess | — | (530) 848 1253 | Other | Arbuckle · Colusa County | — | — |
| C P S | C P S | — | (530) 682 2378 | Other | Princeton · Colusa County | — | — |
| Calfab Steel | Calfab Steel | — | (530) 570 3629 | Other | Colusa · Colusa County | — | — |
| Charles C Geyer DBA Alsco Geyer Irrigation | Alsco Geyer Irrigation | — | (530) 476 2253 | Other | Arbuckle · Colusa County | — | — |
| Clear Line Plumbing | Clear Line Plumbing | — | (530) 966 4577 | Other | Arbuckle · Colusa County | — | — |
| Colusa Mechanical Systems INC | Juan Ramon Arambula Velazquez | — | (530) 407 3830 | Other | Williams · Colusa County | — | — |
| Colusa Plumbing Company | Jesse Saul Munoz | — | (530) 777 8877 | Other | Colusa · Colusa County | — | — |
| Cook Construction Engineering Partnership | Kenneth Maxwell Cook | — | (530) 713 3158 | Other | Stonyford · Colusa County | — | — |
| Dos Rios INC | Ben Russell Phillips | — | (530) 458 8973 | Other | Colusa · Colusa County | — | — |
| Dsb Ag Services LLC DBA Dsb Excavating And Grading | Evan Scott Bell | — | (530) 682 4323 | Other | Williams · Colusa County | — | — |
| G & G Of Lambertville | Rick Ted Greeson | — | (530) 521 2912 | Other | Princeton · Colusa County | — | — |
| Geo L Messick Co INC | Thomas P Reische | — | (530) 458 5144 | Other | Colusa · Colusa County | — | — |
| Glenn Cherry Drilling | Glenn Cherry Drilling | — | (530) 574 5729 | Other | Stonyford · Colusa County | — | — |
| Iannone Drywall | Mathew Vance Iannone | — | (530) 908 5392 | Other | Arbuckle · Colusa County | — | — |
| John J Martin Backhoe Service | John Joseph Martin | — | (530) 682 1630 | Other | Arbuckle · Colusa County | — | — |
| Jv Concrete LLC | Vaca Jorge | — | (530) 870 1653 | Other | Colusa · Colusa County | — | — |
| Mccullough Excavating LLC | David Mitchell Mc Cullough | — | (530) 476 3100 | Other | Arbuckle · Colusa County | — | — |
| Pacific Metal Buildings INC | Eusebio Cabrera Castillo | — | (530) 438 2777 | Other | Maxwell · Colusa County | — | — |
| Price Floor Covering | Price Floor Covering | — | (530) 330 3148 | Other | Colusa · Colusa County | — | — |
| Riordan Concrete Construction | Patrick Conan Riordan | — | (916) 803 2194 | Other | Colusa · Colusa County | — | — |
| Sei Window Coverings | Trevor Ray Smith | smithenterprise@live.com | (510) 375 3114 | Other | Colusa · Colusa County | — | — |
| Smg Communications INC | Zachary Steven Hoyer | — | (530) 619 9155 | Other | Colusa · Colusa County | — | — |
| Streamline Pipe Systems | Streamline Pipe Systems | — | (707) 249 4193 | Other | Williams · Colusa County | — | — |
| The Brick Bros INC | Thomas Bennedic Palomera Canedo | — | (530) 988 6828 | Other | Grimes · Colusa County | — | — |
| West County Plumbing | West County Plumbing | — | (530) 301 7050 | Other | Stonyford · Colusa County | — | — |
| Wren Tile | Wren Tile | — | (916) 847 4559 | Other | Colusa · Colusa County | — | — |
| Wycoff Construction INC | Billy Leroy Wycoff | — | (530) 218 1687 | Other | Stonyford · Colusa County | — | — |