| 201 | Kerr-McGee Oil & Gas Onshore LP | Houston, TX 77046 | Oil & Gas Operator | Oct 2025 |
| 202 | Kissack Resources. LLC | | Oil & Gas Operator | Aug 2025 |
| 203 | KWB Oil Property Management Inc | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2025 |
| 204 | L & J Operating Inc | Gillette, WY 82718 | Oil & Gas Operator | Aug 2016 |
| 205 | L R Company | Casper, WY 82602 | Oil & Gas Operator | Sep 2007 |
| 206 | La Prele Exploration | | Oil & Gas Operator | Oct 1979 |
| 207 | Lappin Oil LLC | Douglas, WY 82633 | Oil & Gas Operator | Sep 2025 |
| 208 | Lario Oil & Gas Company | Odessa, TX 79762 | Oil & Gas Operator | Oct 2025 |
| 209 | Lawson Oil Company | Buckeye, AR 85326 | Oil Operator | Mar 1996 |
| 210 | Lear Petroleum Exploration | | Oil & Gas Operator | Jul 2013 |
| 211 | Levinson Partners Corporation | Denver, CO 80202 | Oil & Gas Operator | Jul 1995 |
| 212 | Lexicon Resources Corporation | | Oil & Gas Operator | Apr 1986 |
| 213 | Loil Oil LLC | Golden, CO 80402 | Oil & Gas Operator | Aug 2025 |
| 214 | Long Trust The | Kilgore, TX 75663 | Oil & Gas Operator | Aug 2008 |
| 215 | Louisiana Land & Exploration Co. | Houston, TX 77210 | Oil & Gas Operator | Sep 2013 |
| 216 | M & K Oil Company LLC | Gillette, WY 82716 | Oil & Gas Operator | Aug 2025 |
| 217 | M & K Oil Operations | | Oil & Gas Operator | Sep 1994 |
| 218 | M-3 Industries | Casper, WY 82602 | Oil & Gas Operator | Jun 2025 |
| 219 | Mack Energy Corporation | Artesia, NM 88211 | Oil & Gas Operator | Aug 2025 |
| 220 | Main Energy, Inc. | Houston, TX 77079 | Oil & Gas Operator | May 2009 |
| 221 | Manx Oil Corporation | Casper, WY 82601 | Oil & Gas Operator | Jun 2010 |
| 222 | Marathon Oil Company | Houston, TX 77252 | Oil & Gas Operator | Aug 2025 |
| 223 | Marmik Oil Company | El Dorado, AR 71730 | Oil & Gas Operator | Jan 2015 |
| 224 | Marquis-Allred Eng Inc | | Oil & Gas Operator | Apr 1992 |
| 225 | Matrix Production Company | Sugar Land, TX 77478 | Oil & Gas Operator | Aug 2025 |
| 226 | Maxim Drilling & Expl Inc | Gillette, WY 82717 | Oil & Gas Operator | Aug 2025 |
| 227 | Mbi Oil & Gas LLC | Dickinson, ND 58601 | Oil & Gas Operator | Aug 2025 |
| 228 | McCulliss Resource Company Inc | Denver, CO 80202 | Oil & Gas Operator | Jun 1999 |
| 229 | McMurry Energy Company | | Oil & Gas Operator | Dec 2001 |
| 230 | McMurry Oil LLC | Denver, CO 80202 | Oil & Gas Operator | Dec 2004 |
| 231 | McO Resources Corporation | | Oil & Gas Operator | Feb 1986 |
| 232 | McQueen Ed & Company Inc | Lindsey, OK 73052 | Oil & Gas Operator | Apr 2014 |
| 233 | McRae & Henry LTD | Golden, CO 80401 | Oil & Gas Operator | May 2022 |
| 234 | Medallion Exploration | Holladay, UT 84117 | Oil & Gas Operator | Dec 2015 |
| 235 | Medicine Bow Operating Company | Houston, TX 77002 | Oil & Gas Operator | Apr 2014 |
| 236 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Oct 2025 |
| 237 | Merrion Oil & Gas Corp | Farmington, NM 87401 | Oil & Gas Operator | Aug 2025 |
| 238 | Methane Productions Inc | Recluse, WY 82725 | Oil & Gas Operator | Apr 2007 |
| 239 | Michigan-Wisconsin Pipe Line Co | | Oil & Gas Operator | Dec 1983 |
| 240 | Mid-Con Energy Operating, LLC | Tulsa, OK 74136 | Oil & Gas Operator | Aug 2025 |
| 241 | Midgard Energy Company | The Woodlands, TX 77380 | Oil & Gas Operator | Dec 2014 |
| 242 | Mitchell Energy Corp | Houston, TX 77002 | Oil & Gas Operator | Aug 2013 |
| 243 | Mobil Expl & Producing North America Inc | | Oil & Gas Operator | Nov 1986 |
| 244 | Mon-Oil Inc | | Oil & Gas Operator | Apr 1996 |
| 245 | Moncrief W A Jr | Fort Worth, TX 76102 | Oil & Gas Operator | Aug 2025 |
| 246 | Montex Drilling Company LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Oct 2025 |
| 247 | Morgan Energy Corporation | Englewood, CO 80110 | Oil & Gas Operator | Mar 2006 |
| 248 | Mustang Oil & Gas Corporation | Wichita Falls, TX 76308 | Oil & Gas Operator | Jul 2021 |
| 249 | MWJ Producing Company | Midland, TX 79701 | Oil & Gas Operator | Jul 1998 |
| 250 | Nance Petroleum Corporation | Billings, MT 59103-7168 | Oil & Gas Operator | Nov 2007 |
| 251 | National Pride Operating | Parker, CO 80134 | Oil & Gas Operator | Dec 2017 |
| 252 | Nautilus Exploration LLC | Denver, CO 80218 | Oil Operator | Mar 2011 |
| 253 | Navigation Powder River LLC | Houston, TX 77024 | Oil & Gas Operator | Aug 2025 |
| 254 | New Horizon Resources LLC | Houston, TX 77057 | Oil & Gas Operator | Oct 2025 |
| 255 | Neward Corporation | FT. Worth, TX 76102 | Oil & Gas Operator | Dec 1997 |
| 256 | Newfield Production Company | The Woodlands, TX 77380-2764 | Oil & Gas Operator | Jul 2022 |
| 257 | Newwoods Petroleum LLC | Oklahoma City, OK 73102 | Oil & Gas Operator | Jan 2016 |
| 258 | Nicolaysen G G Jr | | Oil & Gas Operator | Dec 1995 |
| 259 | Nielson & Associates Inc | Cody, WY 82414 | Oil & Gas Operator | Feb 2016 |
| 260 | Noble Energy Inc | Midland, TX 79706 | Oil & Gas Operator | Oct 2025 |
| 261 | Nonsuch Natural Gas Inc | Naples, FL 34108 | Oil & Gas Operator | Jun 2025 |
| 262 | Nortex Gas & Oil Co | Tulsa, OK 74135 | Oil & Gas Operator | Sep 1993 |
| 263 | North Central Oil Corp | Houston, TX 77252 | Oil & Gas Operator | Dec 2005 |
| 264 | North Finn LLC | Casper, WY 82605 | Oil & Gas Operator | Aug 2025 |
| 265 | Northern Production Co | Gillette, WY 82717 | Oil & Gas Operator | Apr 2013 |
| 266 | Northern Pump Company | Denver, CO 80202-3130 | Oil & Gas Operator | Feb 2006 |
| 267 | Northstar Operating Company Of Texas | Midland, TX 79702 | Oil & Gas Operator | Feb 2008 |
| 268 | Norton Frickey | Lakewood, CO 80215 | Oil & Gas Operator | Dec 2023 |
| 269 | Ocean Energy, Inc. | Houston, TX 77002 | Oil & Gas Operator | Aug 2003 |
| 270 | Oedekoven Water & Hot Oil | Recluse, WY 82725 | Oil & Gas Operator | Sep 2025 |
| 271 | Oilfield Salvage & Service Company | Littleton, CO 80120 | Oil & Gas Operator | Aug 2025 |
| 272 | Okie Crude Company | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2025 |
| 273 | Oryx Energy Company | Dallas, TX 75221 | Oil & Gas Operator | May 2002 |
| 274 | Osborn Heirs Company LTD | San Antonio, TX 78217 | Oil & Gas Operator | Jun 2025 |
| 275 | Oxtex Inc | | Oil & Gas Operator | Oct 1989 |
| 276 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | Oct 2025 |
| 277 | Qep Energy Company | Midland, TX 79701 | Oil & Gas Operator | Jun 2025 |
| 278 | Quinoco Petroleum Inc | | Oil & Gas Operator | Dec 1990 |
| 279 | Ranch Oil Company | West Linn, OR 97068 | Oil & Gas Operator | Aug 2025 |
| 280 | Rathbun Roger | | Oil & Gas Operator | Dec 1993 |
| 281 | Rathpro Inc | Douglas, WY 82633 | Oil & Gas Operator | Feb 1994 |
| 282 | RB Operating Company | Shawnee, OK 74802-1488 | Oil & Gas Operator | Apr 2015 |
| 283 | Reading & Bates Petroleum | | Oil & Gas Operator | Apr 1989 |
| 284 | Remuda Energy Development LLC | Billings, MT 59104 | Oil & Gas Operator | Aug 2025 |
| 285 | Renos Land & Minerals Company | Casper, WY 82601 | Oil & Gas Operator | Oct 2021 |
| 286 | Resources Investment Corp | Denver, CO 80202 | Oil & Gas Operator | Sep 2018 |
| 287 | Reunion Energy Company | Houston, TX 77056 | Oil & Gas Operator | May 1996 |
| 288 | Richardson Operating Company | Denver, CO 80237 | Oil & Gas Operator | Jul 2025 |
| 289 | Rim Operating, Inc. | Englewood, CO 80112 | Oil & Gas Operator | Oct 2025 |
| 290 | Rki Exploration & Production LLC | Tulsa, OK 74172 | Oil & Gas Operator | Oct 2025 |
| 291 | Rme Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Nov 2016 |
| 292 | Robert Hawkins Inc | Kevin, MT 59454 | Oil & Gas Operator | Jul 2025 |
| 293 | Rochelle Oil & Gas | Gillette, WY 82717 | Oil & Gas Operator | Mar 2024 |
| 294 | Rockies Resources Holdings LLC | Lakewood, CO 80228 | Oil & Gas Operator | Jul 2025 |
| 295 | Rocky Mountain Gas Inc | Sheridan, WY 82801 | Gas Operator | Nov 2009 |
| 296 | Rosa Petroleum | Evansville, WY 82636 | Oil Operator | Dec 1995 |
| 297 | Sabine Oil & Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Oct 2025 |
| 298 | Sage Butte PRB Operating, LLC | Denver, CO 80202 | Oil & Gas Operator | Aug 2025 |
| 299 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 300 | Samson Resources Company LLC | Denver, CO 80202 | Oil & Gas Operator | Feb 2021 |