| 201 | Oil Producers In | | Oil & Gas Operator | Dec 1996 |
| 202 | Oil Producers, Inc. Of Kansas | Wichita, KS 67206 | Oil & Gas Operator | Dec 2025 |
| 203 | Oolite Energy Corp | Amarillo, TX 79105 | Oil & Gas Operator | Apr 2022 |
| 204 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | Dec 2025 |
| 205 | P & M Petroleum Management LLC | Denver, CO 80202 | Oil & Gas Operator | Oct 2021 |
| 206 | Palmer Oil, Inc. | Garden City, KS 67846 | Oil & Gas Operator | Sep 2025 |
| 207 | Pantera Energy Company | Amarillo, TX 79101 | Oil & Gas Operator | Dec 2025 |
| 208 | Par Petroleum In | | Oil & Gas Operator | Jun 1993 |
| 209 | Pardee Production Co. | Skiatook, OK 74070 | Oil & Gas Operator | Mar 2021 |
| 210 | Parker & Parsley Development L.P | Midland, TX 79702 | Oil & Gas Operator | Oct 2007 |
| 211 | Patina Oil & Gas Corporation | Denver, CO 80202 | Oil & Gas Operator | May 2016 |
| 212 | Petro-Haley | Borger, TX 79008 | Oil & Gas Operator | Dec 2025 |
| 213 | Petro-Lewis Corp. | | Oil & Gas Operator | Feb 1994 |
| 214 | Petroleum Inc | Wichita, KS 67202 | Oil & Gas Operator | Oct 2021 |
| 215 | Petroleum Incorp | | Oil & Gas Operator | Apr 1993 |
| 216 | Pickrell Drilling Co., Inc. | Wichita, KS 67213 | Oil & Gas Operator | Sep 2025 |
| 217 | Pioneer Exploration, LLC | Houston, TX 77090 | Oil & Gas Operator | Nov 2025 |
| 218 | Pioneer Natural Resources USA Inc | Irving, TX 75039 | Oil & Gas Operator | Sep 2025 |
| 219 | Plains Resources Inc. | Houston, TX 77002 | Oil & Gas Operator | Jul 2008 |
| 220 | Post Petroleum C | | Gas Operator | Nov 1991 |
| 221 | Post Petroleum Company | Oklahoma City, OK 73116 | Oil & Gas Operator | Aug 2013 |
| 222 | Premier Petroleum, Inc. | Wichita, KS 67201 | Oil & Gas Operator | Dec 2009 |
| 223 | Presco Western LLC | Houston, TX 77046 | Oil & Gas Operator | Sep 2025 |
| 224 | Pride Energy Company, A General Partnership | Tulsa, OK 74170 | Oil & Gas Operator | Aug 2021 |
| 225 | Questa Energy Corporation | Amarillo, TX 79159 | Oil & Gas Operator | Dec 2025 |
| 226 | Questar Exploration And Production Company Division Of Questar Urc Company | Oklahoma City, OK 73112 | Oil & Gas Operator | Feb 2023 |
| 227 | Quinque Operatin | | Oil & Gas Operator | Jul 1994 |
| 228 | Quinque Operating Company | Liberal, KS 67905 | Oil & Gas Operator | Sep 2025 |
| 229 | R C Taylor Operating Company LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Nov 2025 |
| 230 | R J Patrick Operating, LLC | Liberal, KS 67905 | Gas Operator | Aug 2006 |
| 231 | R.C.Taylor Companies, Inc. | Oklahoma City, OK 73118 | Oil & Gas Operator | Dec 2019 |
| 232 | R.J. Patrick Operating Co. | | Oil & Gas Operator | Jun 2006 |
| 233 | Rains & Williamson Oil Co Inc | Wichita, KS 67277 | Oil & Gas Operator | Sep 2025 |
| 234 | Rama Operating Company Inc | Stafford, KS 67578 | Oil & Gas Operator | Nov 2025 |
| 235 | Raydon Exploration, Inc. | Oklahoma City, OK 73118 | Oil & Gas Operator | Dec 2025 |
| 236 | Red Hills Energy, LLC | Medicine Lodge, KS 67104 | Oil & Gas Operator | Sep 2025 |
| 237 | Redstone Oil & Gas Company | Dallas, TX 75225 | Oil & Gas Operator | Jan 2020 |
| 238 | Rine Drilling Co | | Oil & Gas Operator | Mar 1994 |
| 239 | Riviera Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | Nov 2025 |
| 240 | Rme Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Nov 2016 |
| 241 | Rosel Energy, Inc. | Liberal, KS 67901 | Oil & Gas Operator | Jul 2004 |
| 242 | Sabre Operating, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Dec 2025 |
| 243 | Sage Drilling Co Inc | Wichita, KS 67202 | Oil & Gas Operator | Nov 1998 |
| 244 | Samson Resources | | Oil Operator | Jan 1994 |
| 245 | Santa Fe Mineral | | Gas Operator | Oct 1994 |
| 246 | Scout Energy Management LLC | Dallas, TX 75240 | Oil & Gas Operator | Dec 2025 |
| 247 | Shepler & Thomas | | Oil & Gas Operator | Oct 1992 |
| 248 | Shepler & Thomas, Inc. | Edmond, OK 73013 | Oil & Gas Operator | Sep 2025 |
| 249 | Sidwell Oil & Ga | | Oil & Gas Operator | May 1993 |
| 250 | Skelly Oil Co | | Oil & Gas Operator | Mar 2005 |
| 251 | Slawson Donald C | Wichita, KS 67202 | Oil & Gas Operator | Apr 2025 |
| 252 | Slawson Explorat | | Oil & Gas Operator | Dec 1996 |
| 253 | Slawson Exploration Company Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Dec 2025 |
| 254 | Southland Royalt | | Oil & Gas Operator | Nov 1993 |
| 255 | Spring, Harry A. | Ardmore, OK 73401 | Oil Operator | Jul 2012 |
| 256 | Staghorn Resources, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2015 |
| 257 | Stallion Energy, Inc. | Houston, TX 77060 | Oil & Gas Operator | Oct 2017 |
| 258 | Stelbar Oil Corporation, Inc. | Wichita, KS 67206 | Oil & Gas Operator | Sep 2025 |
| 259 | Strata Oil Incor | | Oil Operator | Mar 1994 |
| 260 | Stratakan Exploration, LLC | Plainville, KS 67663 | Oil & Gas Operator | Sep 2025 |
| 261 | Sundown Energy, Inc. | Dallas, TX 75240 | Oil & Gas Operator | May 2025 |
| 262 | Sunfire Energy | | Oil & Gas Operator | Sep 2025 |
| 263 | Swenton Michael J | Tulsa, OK 74105 | Oil & Gas Operator | Nov 2025 |
| 264 | Tekenergy Inc | Oklahoma City, OK 73112 | Oil & Gas Operator | Mar 2015 |
| 265 | Terrol Energy In | | Oil Operator | Feb 1993 |
| 266 | Texaco Explorati | | Oil & Gas Operator | Dec 1996 |
| 267 | Texaco Exploration & Prod Inc | Houston, TX 77236 | Oil & Gas Operator | Sep 2025 |
| 268 | Texas Energies Inc | Pratt, KS 67124 | Oil & Gas Operator | Aug 1998 |
| 269 | Three D Resources Inc | Liberal, KS 67905 | Oil & Gas Operator | Sep 2025 |
| 270 | Tomlinson Oil Co Inc | Great Bend, KS 67530 | Oil & Gas Operator | May 2025 |
| 271 | Trans Pacific Oil Corporation | Wichita, KS 67202 | Oil & Gas Operator | Nov 2025 |
| 272 | Tripower Resources LLC | Ardmore, OK 73402 | Oil & Gas Operator | Dec 2025 |
| 273 | Tucker Prod Corp | | Oil & Gas Operator | Dec 1985 |
| 274 | Twin Eagle Petro | | Oil Operator | Aug 1990 |
| 275 | Union Pacific Re | | Oil & Gas Operator | Dec 1996 |
| 276 | Union Pacific Resour | | Oil & Gas Operator | Apr 2002 |
| 277 | Unit Petroleum Company | Tulsa, OK 74170 | Oil & Gas Operator | Dec 2025 |
| 278 | Unknown | Houston, TX 77208 | Oil & Gas Operator | Dec 2023 |
| 279 | Venus Exploration, Inc. | San Antonio, TX 78209 | Oil & Gas Operator | Jul 2013 |
| 280 | Vintage Petroleu | | Oil & Gas Operator | Dec 1995 |
| 281 | Vintage Petroleum, LLC | Houston, TX 77210 | Oil & Gas Operator | Dec 2019 |
| 282 | Viresen & Cochra | | Oil & Gas Operator | Sep 1995 |
| 283 | Western Pacific Farms, Inc. | Copeland, KS 67837 | Oil & Gas Operator | Apr 2020 |
| 284 | Wheeler Oil Company | Sperry, OK 74073-9417 | Oil & Gas Operator | Sep 2025 |
| 285 | Whitaker Enterpr | | Oil Operator | Oct 1992 |
| 286 | Wind River Exploration Inc | Sewickley, PA 15143 | Oil & Gas Operator | Sep 2025 |
| 287 | Woolsey Operating Company, LLC | Wichita, KS 67226 | Oil & Gas Operator | Sep 2025 |
| 288 | Wynn-Crosby Operating, LTD. | Dallas, TX 75201 | Oil & Gas Operator | Dec 2025 |
| 289 | XTO Energy Inc. | Spring, TX 77389 | Oil & Gas Operator | Dec 2025 |
| 290 | Younger Energy Company | Wichita, KS 67206 | Oil & Gas Operator | Dec 2025 |
| 291 | Yucca Petroleum | | Gas Operator | Jan 1994 |
| 292 | Zenergy Inc | Tulsa, OK 74136 | Oil & Gas Operator | Nov 2025 |