| 2 B Fencing | 2 B Fencing | — | (916) 261 2181 | Other | Mc Cloud · Siskiyou County | — | — |
| 4th Gen Flooring | 4th Gen Flooring | — | (530) 598 5817 | Other | Yreka · Siskiyou County | — | — |
| A & M Well Drilling INC | Dianne Theresa Jar Tweedy | — | (530) 905 0695 | Other | Hornbrook · Siskiyou County | — | — |
| A-1 Drains | A-1 Drains | — | (530) 598 2789 | Other | Etna · Siskiyou County | — | — |
| Advantage Paving & Excavating INC | Clayton William Hansen | — | (530) 598 7759 | Other | Yreka · Siskiyou County | — | — |
| Air Construction & Excavation | Darren Paul Rose | — | (530) 842 2224 | Other | Yreka · Siskiyou County | — | — |
| Alpine Engineering | Alpine Engineering | — | (530) 514 1758 | Other | Mc Cloud · Siskiyou County | — | — |
| Altes Engineering INC | Ruth Renee Altes | — | (530) 925 1775 | Other | Mt Shasta · Siskiyou County | — | — |
| Ap Earthworks | Ap Earthworks | — | (530) 514 0908 | Other | Mt Shasta · Siskiyou County | — | — |
| Arnold Krooms & Black Butte Forge | Arnold Jerome Krooms | — | (530) 261 1913 | Other | Mt Shasta · Siskiyou County | — | — |
| B & A Sealcoating | B & A Sealcoating | — | (530) 643 6138 | Other | Yreka · Siskiyou County | — | — |
| B S Fabrication | B S Fabrication | — | (530) 598 5251 | Other | Yreka · Siskiyou County | — | — |
| Basic Fencing INC | John Clarence York | — | (530) 842 2915 | Other | Yreka · Siskiyou County | — | — |
| Ben Vincent's Plumbing Service | Benjamin Ryan Vincent | — | (530) 926 2200 | Other | Mt Shasta · Siskiyou County | — | — |
| Berryhill Contracting INC | Kenneth Alan Berryhill | — | (530) 467 3641 | Other | Etna · Siskiyou County | — | — |
| Black Butte Tree Service LLC | John Charles Mcguire | — | (703) 674 8262 | Other | Mt Shasta · Siskiyou County | — | — |
| Bob Johnson Construction | Robert Thomas Johnson | — | (530) 598 4911 | Other | Yreka · Siskiyou County | — | — |
| Boncella Excavation | Boncella Excavation | — | (530) 842 1946 | Other | Yreka · Siskiyou County | — | — |
| Boudro Construction | Vernon Gene Boudro | — | (530) 598 1580 | Other | Greenview · Siskiyou County | — | — |
| Brendan B Bowling | Brendan B Bowling | — | (530) 340 1790 | Other | Montague · Siskiyou County | — | — |
| Brian Nowdesha Masonry | Brian Nowdesha Masonry | — | (530) 340 5415 | Other | Weed · Siskiyou County | — | — |
| Brooks Drywall | Brooks Drywall | — | (707) 696 0165 | Other | Montague · Siskiyou County | — | — |
| Burfield Engineering | Burfield Engineering | — | (408) 656 4855 | Other | Mount Shasta · Siskiyou County | — | — |
| Buzy Bee Paving Co | Jeffrey Michael Fortner | info@buzybeepaving.com | (530) 926 0897 | Other | Mt Shasta · Siskiyou County | — | — |
| Campbell Grading INC | Barth Charles Campbell | — | (530) 468 4226 | Other | Fort Jones · Siskiyou County | — | — |
| Carlson's Construction INC | Curt Wayne Carlson | — | (530) 598 4640 | Other | Yreka · Siskiyou County | — | — |
| Casey Wade Conner DBA Eddie Conner | Conner Eddie | — | (530) 496 3115 | Other | Klamath River · Siskiyou County | — | — |
| Cone Plumbing INC | Dan Robert Cone | — | (530) 842 7608 | Other | Yreka · Siskiyou County | — | — |
| Custom Crushing Industries INC | Paul Richard Goodwin | — | (530) 842 5544 | Other | Yreka · Siskiyou County | — | — |
| Dan Mcwilliams General Engineering | Dan Mcwilliams General Engineering | — | (530) 925 9690 | Other | Grenada · Siskiyou County | — | — |
| Dean's Tile & Stone | Dean's Tile & Stone | — | (530) 605 6604 | Other | Mount Shasta · Siskiyou County | — | — |
| Don's Plumbing Service | Donald Carl Sr Carle | — | (530) 331 8953 | Other | Fort Jones · Siskiyou County | — | — |
| Downey Trucking & Excavating INC | Jesse Quinn Downey | — | (530) 468 2034 | Other | Fort Jones · Siskiyou County | — | — |
| Everson Flooring | Everson Flooring | — | (530) 925 1860 | Other | Dunsmuir · Siskiyou County | — | — |
| Family Carpet -n- Things | Family Carpet -n- Things | — | (530) 841 1500 | Other | Yreka · Siskiyou County | — | — |
| Fletcher Earthwork | Fletcher Earthwork | — | (925) 323 9721 | Other | Mount Shasta · Siskiyou County | — | — |
| Floor It Enterprises | Andrew William Burnett | — | (530) 925 0471 | Other | Mt Shasta · Siskiyou County | — | — |
| Ftm Engineering | Wyatt David Monday | — | (530) 643 1226 | Other | Fort Jones · Siskiyou County | — | — |
| G S Black INC | Gary Paul Black | — | (530) 598 5800 | Other | Etna · Siskiyou County | — | — |
| Garland Tech | Sean William Garland | — | (530) 988 5200 | Other | Weed · Siskiyou County | — | — |