| Kim's Painting & Electrical | Kim Joon Johnson | — | (805) 748 7571 | Electricians | Sonora · Tuolumne County | — | — |
| King Builders | King Builders | — | (209) 454 9166 | GC, remodel, ADU | Sonora · Tuolumne County | — | — |
| Kirk Giordano Plastering INC | Kirk Pierre Giordano | — | (510) 207 0251 | Other | Sonora · Tuolumne County | — | — |
| Kirk Persing Construction | Kirk Andrew Persing | — | (209) 743 5167 | GC, remodel, ADU | Sonora · Tuolumne County | — | — |
| Klingberg Construction INC | John Richard Jr Klingberg | — | (209) 586 3488 | GC, remodel, ADU | Twain Harte · Tuolumne County | — | — |
| Kourt Graphics | Keith Brandon Godula | kourtgraphics@yahoo.com | (209) 484 4043 | Windows, patio, painters | Sonora · Tuolumne County | — | — |
| Kr Construction | Kenneth Eugene Rodriguez | — | (209) 768 7252 | GC, remodel, ADU | Columbia · Tuolumne County | — | — |
| Kramer Design & Construction | Johnathan James Kramer | — | (209) 588 8321 | GC, remodel, ADU | Twain Harte · Tuolumne County | — | — |
| Kurt Corrigan Const | Kurt Corrigan Const | — | (209) 822 0442 | Other | Jamestown · Tuolumne County | — | — |
| Kurt Edwards Roofing | Kurt Michael Edwards | — | (209) 401 9725 | Other roofers | Groveland · Tuolumne County | — | — |
| Kyle Dahlin Construction | Kyle Duaine Dahlin | — | (209) 768 0438 | GC, remodel, ADU | Sonora · Tuolumne County | — | — |
| L R Hiatt Construction Co | Lewis R Hiatt | — | (209) 564 9953 | GC, remodel, ADU | Sonora · Tuolumne County | — | — |
| L T Energy Construction Solutions INC | Lenny Trakhter | — | (415) 334 8075 | GC, remodel, ADU | Groveland · Tuolumne County | — | — |
| L T L Construction Services | Leslie Tyler Latham | — | (209) 588 6194 | GC, remodel, ADU | Sonora · Tuolumne County | — | — |
| La Forge Plumbing | La Forge Plumbing | — | (408) 761 5676 | GC, remodel, ADU | Twain Harte · Tuolumne County | — | — |
| Ladislav Niedziolka | Ladislav Niedziolka | — | (209) 352 9590 | HVAC | Sonora · Tuolumne County | — | — |
| Lafayette Construction | Dennis James Lafayette | — | (209) 604 6510 | Electricians | Sonora · Tuolumne County | — | — |
| Lafayette Construction/wise Energy Solutions | Lafayette Construction/wise Energy Solutions | — | (209) 297-3196 | Electricians | Sonora · Tuolumne County | — | — |
| Larry Buck Electrical Contractor | Laurence Joseph Buck | — | (209) 985 2870 | Electricians | Twain Harte · Tuolumne County | — | — |
| Lars Betzenderfer Construction INC | Lars Bjorseth Betzenderfer | — | (209) 770 3755 | GC, remodel, ADU | Sonora · Tuolumne County | — | — |
| Larsson Construction | Korey Aron Larsson | — | (209) 768 0998 | GC, remodel, ADU | Twain Harte · Tuolumne County | — | — |
| Lee Family Home Repair LLC | Darvis Beuford Lee | — | (209) 559 5298 | Other roofers | Sonora · Tuolumne County | — | — |
| Lee Smail Construction | Phillip Lee Smail | — | (209) 352 8050 | GC, remodel, ADU | Sonora · Tuolumne County | — | — |
| Leed Construction Management INC | Robert Brandon Mercade | — | (619) 495 0318 | Electricians | Twain Harte · Tuolumne County | — | — |
| Left Coast Land Clearing | Sasha Joaquin Farkas | — | (209) 536 9174 | Tree | Sonora · Tuolumne County | — | — |
| Lennen Associates | Robert James Lennen | — | (209) 962 4642 | GC, remodel, ADU | Groveland · Tuolumne County | — | — |
| Leslie Tree Service | Colleen Marie Leslie | — | (209) 840 1827 | Tree | Sonora · Tuolumne County | — | — |
| Lewellen Excavation | Lewellen Excavation | — | (209) 768 8652 | Other | Sonora · Tuolumne County | — | — |
| Liberty Construction Company | Douglas G Carlen | — | (209) 928 4422 | GC, remodel, ADU | Twain Harte · Tuolumne County | — | — |
| Lindahn Enterprises | Roger Edward Lindahn | — | (408) 839 8562 | GC, remodel, ADU | Sonora · Tuolumne County | — | — |
| Live Wire Electric | Villavicencio Victor | — | (209) 586 2426 | Electricians | Soulsbyville · Tuolumne County | — | — |
| Living Iron Steel Works | Living Iron Steel Works | — | (530) 417 5661 | Other | Tuolumne · Tuolumne County | — | — |
| Livingstone Earthwerx | Livingstone Earthwerx | — | (209) 897 1015 | Other | Sonora · Tuolumne County | — | — |
| Logic Construction | Stefan Charles Logie | — | (831) 238 5560 | GC, remodel, ADU | Sonora · Tuolumne County | — | — |
| Longeway Construction | Jesse Wade Longeway | — | (209) 352 9429 | GC, remodel, ADU | Sonora · Tuolumne County | — | — |
| Lovett Excavating INC | Steven Jay Lovett | — | (209) 743 0186 | GC, remodel, ADU | Twain Harte · Tuolumne County | — | — |
| Low Construction LLC | Levi Victor Pomai Low | — | (209) 694 6785 | GC, remodel, ADU | Sonora · Tuolumne County | — | — |
| Lucas Building Corporation | Douglas Anthony Lucas | — | (209) 785 3211 | GC, remodel, ADU | Sonora · Tuolumne County | — | — |
| Lucas Divine Construction | Lucas Allen Divine | — | (209) 743 9302 | GC, remodel, ADU | Jamestown · Tuolumne County | — | — |
| Lugo's Expert Tree Service | Gustavo Lugo | — | (510) 706 0802 | Tree | Tuolumne · Tuolumne County | — | — |