| Clyde Construction INC | Andrew James Clyde | — | (707) 206 2424 | GC, remodel, ADU | Mount Shasta · Siskiyou County | — | — |
| Cody Clure Construction INC | Cody Dean Clure | — | (530) 526 5436 | GC, remodel, ADU | Mt Shasta · Siskiyou County | — | — |
| Cone Plumbing INC | Dan Robert Cone | — | (530) 842 7608 | Other | Yreka · Siskiyou County | — | — |
| Conley Painting | Conley Painting | — | (530) 340 5648 | Windows, patio, painters | Yreka · Siskiyou County | — | — |
| Constructioneer Tony | Constructioneer Tony | — | (530) 598 4787 | GC, remodel, ADU | Yreka · Siskiyou County | — | — |
| Costner Construction | Grover Charles Costner | — | (541) 601 2922 | GC, remodel, ADU | Grenada · Siskiyou County | — | — |
| Craig Fisher Painting | Craig Fisher Painting | — | (530) 938 4376 | Windows, patio, painters | Weed · Siskiyou County | — | — |
| Curly Culp Construction | Ronald Burdette Jr Culp | — | (530) 598 2277 | Other roofers | Yreka · Siskiyou County | — | — |
| Custom Crushing Industries INC | Paul Richard Goodwin | — | (530) 842 5544 | Other | Yreka · Siskiyou County | — | — |
| D P Construction | David Warren Peterson | — | (530) 859 1355 | GC, remodel, ADU | Weed · Siskiyou County | — | — |
| Dan Mcwilliams General Engineering | Dan Mcwilliams General Engineering | — | (530) 925 9690 | Other | Grenada · Siskiyou County | — | — |
| Daniel Corson DBA Dressler Heating & Cooling | Dressler Heating & Cooling | — | (530) 598 2179 | HVAC | Yreka · Siskiyou County | — | — |
| Dave Camp Construction | David Bernard Camp | — | (530) 964 2267 | GC, remodel, ADU | Mc Cloud · Siskiyou County | — | — |
| David Kische Painting | David Kische Painting | — | (530) 459-5910 | Windows, patio, painters | Montague · Siskiyou County | — | — |
| De Vine Construction | Deanna Lynn Hoppin | — | (530) 925 9952 | GC, remodel, ADU | Weed · Siskiyou County | — | — |
| Dean's Tile & Stone | Dean's Tile & Stone | — | (530) 605 6604 | Other | Mount Shasta · Siskiyou County | — | — |
| Derick Girven Construction | Derick Richard Girven | — | (530) 598 5150 | GC, remodel, ADU | Etna · Siskiyou County | — | — |
| Derrik Bennett Construction | Derrik William Bennett | — | (530) 340 2116 | GC, remodel, ADU | Yreka · Siskiyou County | — | — |
| Dickens Electric Company | Jefferey Forbes Dickens | — | (530) 339 2437 | Electricians | Weed · Siskiyou County | — | — |
| Dickinson Builders INC | Kenneth Wade Dickinson | — | (530) 467 4120 | GC, remodel, ADU | Etna · Siskiyou County | — | — |
| Diversified Electric INC | John Harrison Poston | — | (530) 926 7901 | Electricians | Mt Shasta · Siskiyou County | — | — |
| Dolf Construction | Scott Anthony Dolf | — | (530) 925 0313 | GC, remodel, ADU | Mt Shasta · Siskiyou County | — | — |
| Don's Plumbing Service | Donald Carl Sr Carle | — | (530) 331 8953 | Other | Fort Jones · Siskiyou County | — | — |
| Done Right Painting & Decorating | Done Right Painting & Decorating | — | (530) 261 1777 | Windows, patio, painters | Mt Shasta · Siskiyou County | — | — |
| Double Eagle Construction | Edward Thomas Johnson | doubleeagleconst@gmail.com | (530) 240 5514 | GC, remodel, ADU | Weed · Siskiyou County | — | — |
| Double S Construction | Nicholas Adam James Stanley | — | (530) 859 2154 | GC, remodel, ADU | Mt Shasta · Siskiyou County | — | — |
| Downey Heating & Cooling INC | David Dale Downey | — | (530) 468 4288 | HVAC | Etna · Siskiyou County | — | — |
| Downey Trucking & Excavating INC | Jesse Quinn Downey | — | (530) 468 2034 | Other | Fort Jones · Siskiyou County | — | — |
| Ducharme Co | Erik Clifton Ducharme | — | (530) 340 3842 | GC, remodel, ADU | Etna · Siskiyou County | — | — |
| Eagle Ranch Construction | Dylan Eugene Luckey | — | (530) 905 0953 | GC, remodel, ADU | Montague · Siskiyou County | — | — |
| Elite Rigging Tree Trimming | Elite Rigging Tree Trimming | — | (530) 340 3217 | Tree | Yreka · Siskiyou County | — | — |
| Eric Rideout Construction Company | Eric Wesley Rideout | — | (530) 261 2064 | GC, remodel, ADU | Mt Shasta · Siskiyou County | — | — |
| Evan Drake Craft Carpentry & Sauna | Evan Anthony Drake | — | (530) 859 5359 | GC, remodel, ADU | Mount Shasta · Siskiyou County | — | — |
| Evans Building & Excavating INC | Amy Lea Evans | — | (530) 842 5106 | Other roofers | Yreka · Siskiyou County | — | — |
| Everson Flooring | Everson Flooring | — | (530) 925 1860 | Other | Dunsmuir · Siskiyou County | — | — |
| Fab Electric And Remote Cabling | Fred A Butcher | — | (530) 938 3402 | Electricians | Weed · Siskiyou County | — | — |
| Fabbrini's Wood Products | Fabbrini's Wood Products | — | (530) 227 7747 | GC, remodel, ADU | Mt Shasta · Siskiyou County | — | — |
| Fall River Builder | Fall River Builder | — | (530) 545 2910 | GC, remodel, ADU | Weed · Siskiyou County | — | — |
| Family Carpet -n- Things | Family Carpet -n- Things | — | (530) 841 1500 | Other | Yreka · Siskiyou County | — | — |
| Fisher Roofing | Colton James Fisher | impallari@gmail.com | (530) 643 3382 | Other roofers | Fort Jones · Siskiyou County | — | — |