| 201 | MRD Operating LLC (Delaware) | Houston, TX 77010 | Oil & Gas Operator | Jul 2015 |
| 202 | Mull Drilling Company | Wichita, KS 67206 | Oil & Gas Operator | Nov 2025 |
| 203 | Mustang Resources LLC | Houston, TX 77046 | Oil & Gas Operator | Nov 2025 |
| 204 | MWJ Producing Company | Midland, TX 79701 | Oil & Gas Operator | Jul 1998 |
| 205 | Nance Petroleum Corporation | Billings, MT 59103-7168 | Oil & Gas Operator | Nov 2007 |
| 206 | National Energy Group Inc | Dallas, TX 75206 | Oil & Gas Operator | Sep 2014 |
| 207 | Natural Gas Corp Of California | Vernal, UT 84078 | Oil & Gas Operator | Dec 1989 |
| 208 | Natural Gas Processing Company | Worland, WY 82401 | Oil & Gas Operator | Dec 2025 |
| 209 | Newport Oil Corporation | Clearwater, FL 33755 | Oil & Gas Operator | Jul 2011 |
| 210 | Noble Energy Inc | Midland, TX 79706 | Oil & Gas Operator | Feb 2026 |
| 211 | North Finn LLC | Casper, WY 82605 | Oil & Gas Operator | Dec 2025 |
| 212 | North Shore Exploration & Prod LLC | Broomfield, CO 80021 | Oil & Gas Operator | Dec 2025 |
| 213 | Northwest Exploration | | Oil & Gas Operator | Dec 1984 |
| 214 | Ocean Energy Inc | Houston, TX 77002 | Oil & Gas Operator | Aug 2003 |
| 215 | Okie Crude Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2025 |
| 216 | Omimex Petroleum Inc (De) | Fort Worth, TX 76120 | Oil & Gas Operator | Aug 2020 |
| 217 | Oryx Energy Company | Dallas, TX 75221 | Oil & Gas Operator | May 2002 |
| 218 | Ovintiv USA Inc. | Denver, CO 80202 | Oil & Gas Operator | Feb 2026 |
| 219 | Oxtex Inc | | Oil & Gas Operator | Oct 1989 |
| 220 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | Feb 2026 |
| 221 | P & M Petroleum Management LLC | Denver, CO 80202 | Oil & Gas Operator | Oct 2021 |
| 222 | P & P Producing Inc | Midland, TX 79702 | Oil & Gas Operator | Feb 2015 |
| 223 | P.O.&G. Operating, LLC | Houston, TX 77057 | Oil & Gas Operator | Feb 2026 |
| 224 | Pacific Enterprises Oil Co USA | Dallas, TX 75201 | Oil & Gas Operator | Feb 2001 |
| 225 | Pacific Transmission Supply | | Oil & Gas Operator | Dec 1987 |
| 226 | Patina Oil & Gas Corporation | Denver, CO 80202 | Oil & Gas Operator | May 2016 |
| 227 | Patrick Petroleum Co. | Jackson, MI 49201 | Oil & Gas Operator | Nov 1993 |
| 228 | Peakview Oil Company LLC | Denver, CO 80202 | Gas Operator | Dec 2025 |
| 229 | Pedco Resources Company | Tulsa, OK 74170 | Oil & Gas Operator | Mar 2008 |
| 230 | Pelican Dome Exploration | Harahan, LA 70123 | Oil & Gas Operator | Jun 1997 |
| 231 | Petra Petroleum Inc | Littleton, CO 80160-0319 | Oil & Gas Operator | Jun 2005 |
| 232 | Petral Exploration Inc LLC | Denver, CO 80217 | Oil & Gas Operator | May 2007 |
| 233 | Petro Search Exploration Corp | | Oil & Gas Operator | May 1993 |
| 234 | Petrogulf Corporation | Denver, CO 80202 | Oil & Gas Operator | Feb 2026 |
| 235 | Petrohawk Operating Company | Houston, TX 77056 | Oil & Gas Operator | Oct 2021 |
| 236 | Petroleum Corp Of Delaware The | | Oil & Gas Operator | May 1991 |
| 237 | Petroleum Inc | Wichita, KS 67202 | Oil & Gas Operator | Oct 2021 |
| 238 | Phillips Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Mar 2013 |
| 239 | Phoenix Resources Co | | Oil & Gas Operator | Jun 1984 |
| 240 | Pioneer Natural Resources USA Inc | Irving, TX 75039 | Oil & Gas Operator | Sep 2025 |
| 241 | Plains Petroleum Operating Co | Denver, CO 80202 | Oil & Gas Operator | Dec 2014 |
| 242 | Pogo Producing Company LLC | Houston, TX 77002 | Oil & Gas Operator | Dec 2025 |
| 243 | Polfam Exploration Co | Denver, CO 80204 | Oil & Gas Operator | Mar 2007 |
| 244 | Polumbus Corporation | Denver, CO 80202 | Oil & Gas Operator | Sep 1982 |
| 245 | Prenalta Corporation | Terrytown, NY 10591 | Oil & Gas Operator | Jan 1997 |
| 246 | Prime Operating Company | Midland, TX 79705 | Oil & Gas Operator | Feb 2026 |
| 247 | Qep Energy Company | Midland, TX 79701 | Oil & Gas Operator | Nov 2025 |
| 248 | Rainbow Oil Company | | Oil & Gas Operator | Aug 1999 |
| 249 | Ranch Oil Company | West Linn, OR 97068 | Oil & Gas Operator | Jan 2026 |
| 250 | Ranger Holdings Co | | Oil & Gas Operator | Jul 1993 |
| 251 | Rangeview Resources Operating Co | | Oil & Gas Operator | Nov 2025 |
| 252 | RB Operating Company | Shawnee, OK 74802-1488 | Oil & Gas Operator | Apr 2015 |
| 253 | Reading & Bates Petroleum | | Oil & Gas Operator | Apr 1989 |
| 254 | Reserve Oil & Gas Company | | Oil & Gas Operator | Jul 1981 |
| 255 | Reserve Operating Corp. | Houston, TX 77040 | Oil & Gas Operator | Feb 2026 |
| 256 | Riata Energy, Inc. | Oklahoma City, OK 73101 | Oil & Gas Operator | Nov 2006 |
| 257 | Richardson Operating Company | Denver, CO 80237 | Oil & Gas Operator | Nov 2025 |
| 258 | Rim Operating, Inc. | Englewood, CO 80112 | Oil & Gas Operator | Feb 2026 |
| 259 | Rio Blanco Energy, Inc. | Littleton, CO 80121 | Oil & Gas Operator | Oct 2002 |
| 260 | River Gas Corporation | Tuscaloosa, AL 35406-2233 | Gas Operator | Dec 2000 |
| 261 | Rme Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Nov 2016 |
| 262 | Robert Hawkins Inc | Kevin, MT 59454 | Oil & Gas Operator | Dec 2025 |
| 263 | Rock Creek Resources LLC | Englewood, CO 80112 | Oil & Gas Operator | Dec 2021 |
| 264 | Rocky Mountain Operating Co Inc | Littleton, CO 80121 | Oil & Gas Operator | Dec 2011 |
| 265 | Roemer Oil Company | Denver, CO 80202 | Oil & Gas Operator | Nov 1998 |
| 266 | Sabine Oil & Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Feb 2026 |
| 267 | Saga Petroleum LLC Of Colorado | Norman, OK 73072 | Oil & Gas Operator | Feb 2026 |
| 268 | Salt Creek Operating LLC | FT Morgan, CO 80701 | Oil & Gas Operator | Mar 2020 |
| 269 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 270 | Samson Oil & Gas USA Inc | Denver, CO 80202 | Oil & Gas Operator | Dec 2025 |
| 271 | Samson Resources Company LLC | Denver, CO 80202 | Oil & Gas Operator | Feb 2021 |
| 272 | San Marco Petroleum Inc | Denver, CO 80293 | Oil & Gas Operator | Dec 2025 |
| 273 | Sands-American Corp | | Oil & Gas Operator | Jan 1990 |
| 274 | Shell Rocky Mountain Production LLC | Pinedale, WY 82941 | Oil & Gas Operator | Dec 2008 |
| 275 | Shenandoah Energy Inc | Denver, CO 80265-1050 | Oil & Gas Operator | Dec 2014 |
| 276 | Slaughter J M Oil Company | Fort Worth, TX 76116 | Oil & Gas Operator | Jan 2001 |
| 277 | SM Energy Company | Midland, TX 79707 | Oil & Gas Operator | Feb 2026 |
| 278 | Smokey Oil Company Inc | Casper, WY 82601 | Oil & Gas Operator | Dec 1996 |
| 279 | Snyder Oil Corporation | Houston, TX 77024 | Oil & Gas Operator | Mar 2008 |
| 280 | Southland Royalty Company | Houston, TX 77210 | Oil & Gas Operator | Sep 2011 |
| 281 | Southland Royalty Company LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Jul 2021 |
| 282 | St Michael Exploration | | Oil & Gas Operator | Jun 1987 |
| 283 | Stanley Energy Inc | Denver, CO 80203 | Oil & Gas Operator | Aug 2004 |
| 284 | Stephens Production Company | The Woodlands, TX 77381 | Oil & Gas Operator | Dec 2025 |
| 285 | Stone Energy Corporation | Denver, CO 80202-2828 | Oil & Gas Operator | Oct 2014 |
| 286 | Stone Energy LLC | Denver, CO 80202 | Oil & Gas Operator | May 2005 |
| 287 | Summit Gas Resources Inc | Sheridan, WY 82801 | Gas Operator | Dec 2023 |
| 288 | Sunshine Valley Petroleum | Casper, WY 82605 | Oil & Gas Operator | Dec 2025 |
| 289 | Survivor Oil Inc | Tulsa, OK 74133 | Oil & Gas Operator | Sep 2007 |
| 290 | Swepi LP | Houston, TX 77079 | Oil & Gas Operator | Jul 2020 |
| 291 | Synergy Operating LLC | Farmington, NM 87499 | Oil & Gas Operator | Nov 2025 |
| 292 | Tbi Exploration Inc | Englewood, CO 801556525 | Oil & Gas Operator | Jun 2011 |
| 293 | Tenneco Oil Company | Oklahoma City, OK 73125 | Oil & Gas Operator | Nov 2025 |
| 294 | Terex Energy Corporation | Casper, WY 82602 | Oil & Gas Operator | Aug 2019 |
| 295 | Tex/Con Oil & Gas Company | Houston, TX 77074 | Oil & Gas Operator | Feb 2001 |
| 296 | Texaco Exploration & Prod | Midland, TX 79702 | Oil & Gas Operator | Aug 2002 |
| 297 | Texas Gas Exploration Corp. | | Oil & Gas Operator | Nov 1986 |
| 298 | Texas Oil & Gas Corporation | Dallas, TX 75201 | Oil & Gas Operator | Feb 2001 |
| 299 | TGX Corporation | Houston, TX 77002 | Oil & Gas Operator | Sep 2004 |
| 300 | Timberline Production Company LLC | Casper, WY 82601 | Oil & Gas Operator | Oct 2020 |