| 1 | Peters Drilling And Pump Service | 380 | 1,814 | 11,563 |
| 2 | American Well Drilling And Pump Service | 368 | 406 | 439 |
| 3 | Gary C Tanko Well Drilling Inc. | 342 | 4,734 | 12,022 |
| 4 | Diamond Well Drilling Company Inc. | 160 | 492 | 1,150 |
| 5 | Goodell Well & Pump Service | 25 | 52 | 342 |
| 6 | Cascade Drilling L P | 11 | 12 | 2,827 |
| 7 | Bruce Mackay Pump & Well Service Inc. | 10 | 33 | 260 |
| 8 | Guardino Well Drilling Inc. | 10 | 10 | 1,736 |
| 9 | Cascade Drilling LP | 9 | 17 | 826 |
| 10 | Nor - Cal Pump & Well Drilling Inc. | 9 | 9 | 248 |
| 11 | Top Hat Well Drilling | 9 | 9 | 31 |
| 12 | Phifer Well Service | 7 | 7 | 37 |
| 13 | Sullivan Drilling Inc. | 6 | 6 | 1,387 |
| 14 | Gregg Drilling LLC | 5 | 5 | 558 |
| 15 | Wildrose Drilling LLC | 4 | 4 | 102 |
| 16 | Stonehouse Well Drilling | 3 | 3 | 157 |
| 17 | Triangle Well Drilling | 2 | 25 | 2,894 |
| 18 | Eaton Drilling Co. LLC | 2 | 11 | 3,793 |
| 19 | Jensen Kelin Drilling | 2 | 2 | 94 |
| 20 | Kleinfelder Inc. | 2 | 2 | 54 |
| 21 | Kile's Well Drilling | 1 | 213 | 943 |
| 22 | Tanko Gary C Well Drilling | 1 | 104 | 284 |
| 23 | Well Industries Inc. | 1 | 6 | 558 |
| 24 | Castle Construction & Well Drilling Inc. | 1 | 2 | 142 |
| 25 | American Construction And Supply Inc. | 1 | 1 | 1,685 |
| 26 | Gregory Drilling Incorporated | 1 | 1 | 143 |
| 27 | Kvilhaug Drilling & Pump Inc. | 1 | 1 | 327 |
| 28 | Mid State Pump And Drilling | 1 | 1 | 74 |
| 29 | Vannucci Technologies | 1 | 1 | 66 |
| 30 | Hedman Drilling | 1 | 1 | 126 |
| 31 | Pitcher Drilling Co. | 1 | 1 | 1,232 |
| 32 | Bfr Associates | — | 3,306 | 5,621 |
| 33 | Wayne Drilling Co. | — | 861 | 1,113 |
| 34 | Redhawk Drilling | — | 545 | 1,197 |
| 35 | Wayne Environmental Drilling Company Inc. | — | 524 | 664 |
| 36 | Mel Meyer | — | 338 | 101,127 |
| 37 | Patten Well Drilling | — | 228 | 421 |
| 38 | American Well Drilling | — | 193 | 307 |
| 39 | J Field Drilling Co. | — | 149 | 275 |
| 40 | D W Moore Well Drilling | — | 146 | 170 |
| 41 | Allmon C T Development Co. | — | 95 | 153 |
| 42 | Fox Loomis Incorporated | — | 79 | 225 |
| 43 | Tahoe Pump & Drilling Inc. | — | 72 | 358 |
| 44 | Beymer Well Service | — | 65 | 2,921 |
| 45 | Signal Drilling Company | — | 55 | 8,301 |
| 46 | G Gakin Well Drilling | — | 46 | 147 |
| 47 | Starr Drilling And Pump Co. | — | 45 | 875 |
| 48 | Cascade Drilling Inc. - California | — | 43 | 3,167 |
| 49 | H T Ted Herr | — | 40 | 776 |
| 50 | Bertram Drilling Inc. | — | 39 | 1,171 |
| 51 | Preston Well Drilling | — | 34 | 698 |
| 52 | General Development | — | 34 | 65 |
| 53 | V J Mcgrew | — | 30 | 147 |
| 54 | Gregg Drilling & Testing Inc. | — | 28 | 4,828 |
| 55 | R Wilder Gen Cont | — | 28 | 409 |
| 56 | Woodward Drilling Company Inc. | — | 25 | 1,542 |
| 57 | Frank P Conley | — | 24 | 218 |
| 58 | Water Well Drilling Cont | — | 22 | 263 |
| 59 | Bill Rambeau Pump & Well Drilling | — | 19 | 288 |
| 60 | Paul Williams And Sons | — | 19 | 175 |
| 61 | Wilder, R., Drilling Company | — | 18 | 1,089 |
| 62 | Kearns-Rivard Well Drilling | — | 17 | 291 |
| 63 | Tanko Bros Inc. | — | 16 | 2,617 |
| 64 | Allen Drilling Co. | — | 16 | 1,295 |
| 65 | Beylik Drilling & Pump Service | — | 16 | 1,267 |
| 66 | ED Fields Water Well Drilling | — | 14 | 234 |
| 67 | Kennedy, Bryant, Drilling Co. | — | 14 | 50 |
| 68 | Sargent Drilling | — | 13 | 442 |
| 69 | John Linn Drilling, Co. | — | 12 | 428 |
| 70 | Fredrick Mark Pump & Supply Co. | — | 11 | 295 |
| 71 | Weston E Dawson | — | 11 | 147 |
| 72 | Fred W Porter & Sons | — | 11 | 105 |
| 73 | Teg - Northern California Inc. | — | 11 | 27 |
| 74 | Johnson Drilling Co. | — | 10 | 11,865 |
| 75 | Robert Dawson Drilling & Pumps | — | 10 | 1,415 |
| 76 | Alva E Morgan | — | 9 | 45 |
| 77 | Castlio Drilling Co. | — | 9 | 29 |
| 78 | Irwin Well Drilling | — | 8 | 1,906 |
| 79 | Tanko Well Drilling | — | 8 | 3,311 |
| 80 | Confluence Environmental Inc. | — | 8 | 65 |
| 81 | Testamerica Drilling Corp | — | 8 | 378 |
| 82 | Environmental West Drilling | — | 8 | 38 |
| 83 | Seebeck M E | — | 7 | 567 |
| 84 | Island Drilling | — | 7 | 221 |
| 85 | Star Well Drilling & Pump Co. | — | 7 | 122 |
| 86 | C & M Drilling Co. | — | 7 | 41 |
| 87 | Mitchell Drilling Environmental Corp | — | 6 | 199 |
| 88 | Blain & Imbach Well Drilling | — | 6 | 168 |
| 89 | Robert Allen Nix Well Drilling | — | 5 | 373 |
| 90 | Dicken's Drilling | — | 5 | 490 |
| 91 | Ken Hickman Well Drilling | — | 5 | 29 |
| 92 | Zim Industries Inc. Dba Bakersfield Well & Pump Co. | — | 4 | 1,716 |
| 93 | Waters Backhoe & Dozer Service | — | 4 | 110 |
| 94 | Valley Pump & Motor Works Inc. | — | 4 | 181 |
| 95 | Allen Drilling & Equipment Co. | — | 4 | 311 |
| 96 | Heer Nar S | — | 4 | 245 |
| 97 | E E Luhdorff | — | 4 | 155 |
| 98 | Scott Xxx PC Exploration Inc. | — | 4 | 154 |
| 99 | Points West Drilling | — | 4 | 78 |
| 100 | Maggiora Bros Drilling Inc. | — | 3 | 4,674 |
| 101 | Layne Christensen Company | — | 3 | 2,362 |
| 102 | Britton Exploration | — | 3 | 36 |
| 103 | W D C Exploration & Wells | — | 3 | 2,421 |
| 104 | Aufdenkamp Drilling Inc. | — | 3 | 2,330 |
| 105 | Hunt Drilling Company Inc. | — | 3 | 1,213 |
| 106 | Rockwell Drilling Co. | — | 3 | 244 |
| 107 | Humboldt Drilling & Pump Co. | — | 3 | 131 |
| 108 | Brown Brothers Drilling | — | 3 | 102 |
| 109 | James W Imbach Well Drilling | — | 3 | 86 |
| 110 | W E Blain | — | 3 | 82 |
| 111 | Butte Pump Service | — | 3 | 26 |
| 112 | Water-Tech Well Drilling | — | 2 | 665 |
| 113 | Pambeau Pump & Well | — | 2 | 405 |
| 114 | Olson's Plbg & Heating | — | 2 | 308 |
| 115 | Layne-Western Co. Inc. | — | 2 | 255 |
| 116 | American Well & Pump Service | — | 2 | 254 |
| 117 | Steve's Pumps & Well Drilling Inc. | — | 2 | 162 |
| 118 | Melvin L Lukins | — | 2 | 93 |
| 119 | Trinity Source Group Inc. | — | 2 | 67 |
| 120 | Ben Barrow Company | — | 2 | 49 |
| 121 | Pollock's Drilling & Pump Service | — | 2 | 39 |
| 122 | Big Valley Drilling & Exploration Co. | — | 2 | 32 |
| 123 | Roadrunner Drilling & Pump Company Inc. | — | 1 | 205 |
| 124 | Enloe Well Drilling | — | 1 | 279 |
| 125 | Boart Longyear Company | — | 1 | 172 |
| 126 | Drilling Services Inc. | — | 1 | 63 |
| 127 | Bill Belknap | — | 1 | 2,758 |
| 128 | Dunn Jack Inc. | — | 1 | 1,424 |
| 129 | D Hedman & Co. | — | 1 | 1,305 |
| 130 | Arrow Well Drilling | — | 1 | 1,202 |
| 131 | Beaman & Son Pump Co. | — | 1 | 990 |
| 132 | Western Well Drilling Co. Ltd | — | 1 | 842 |
| 133 | Woods Well Drilling | — | 1 | 755 |
| 134 | All Well Abandonment | — | 1 | 607 |
| 135 | Sutter Pump Works | — | 1 | 449 |
| 136 | Tom Hunt Drilling Co. | — | 1 | 418 |
| 137 | Resonantsonic International Inc. | — | 1 | 397 |
| 138 | Flynn Well Drilling | — | 1 | 252 |
| 139 | Harris A J Co. | — | 1 | 239 |
| 140 | Cranmer & Ellis Water Well Drillers | — | 1 | 197 |
| 141 | Robert Garcia Well & Pump Co. | — | 1 | 192 |
| 142 | American River Well Drilling | — | 1 | 180 |
| 143 | Thomas E Mccaw Well Drilling | — | 1 | 141 |
| 144 | Taylor & Taber Drillers | — | 1 | 139 |
| 145 | Allen's Drilling & Pump Service | — | 1 | 134 |
| 146 | W L Kirchgater | — | 1 | 98 |
| 147 | Stang Hydronics Inc. | — | 1 | 56 |
| 148 | Westex | — | 1 | 40 |
| 149 | Keener Exploration Drilling Co. | — | 1 | 37 |
| 150 | William B Zuver | — | 1 | 37 |
| 151 | B & F Drilling | — | 1 | 35 |
| 152 | Levy Matthews & Son | — | 1 | 35 |
| 153 | North State Well & Pump | — | 1 | 30 |
| 154 | Nor-Cal Pump & Well Service | — | 1 | 26 |
| 155 | Gary D Lowe | — | 1 | 25 |