| 201 | Lance Oil & Gas Company Inc | Kirtland, NM 87417 | Oil & Gas Operator | Mar 2013 |
| 202 | Lear Petroleum Exploration | | Oil & Gas Operator | Jul 2013 |
| 203 | Legacy Reserves Operating LP | Denver, CO 80201 | Oil & Gas Operator | Jul 2025 |
| 204 | Levinson Partners Corporation | Denver, CO 80202 | Oil & Gas Operator | Jul 1995 |
| 205 | Linn Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Jan 2019 |
| 206 | Lodestone Operating | Portland, TX 78374 | Oil & Gas Operator | Mar 2025 |
| 207 | Luff Exploration | Denver, CO 80203 | Oil & Gas Operator | Dec 2006 |
| 208 | Lyco Operating Company | Dallas, TX 75206 | Gas Operator | Dec 1997 |
| 209 | M & C Oil Inc | Indianola, NE 68034 | Oil & Gas Operator | Nov 2013 |
| 210 | M & G Oil And Gas Inc | Llabarge, WY 83123 | Oil & Gas Operator | Apr 2023 |
| 211 | M G Production Co | Rock Springs, WY 82901 | Oil Operator | Dec 1999 |
| 212 | Macum Energy Inc | Billings, MT 59104 | Oil & Gas Operator | Aug 2021 |
| 213 | Mak-J Energy Wyoming LLC | Denver, CO 80620 | Oil & Gas Operator | Nov 2012 |
| 214 | Mapco Oil Company | | Oil & Gas Operator | Jan 1985 |
| 215 | Marathon Oil Company | Houston, TX 77252 | Oil & Gas Operator | May 2025 |
| 216 | Martin Exploration | Westminster, CO 80030 | Oil & Gas Operator | Dec 1993 |
| 217 | Matrix Production Company | Sugar Land, TX 77478 | Oil & Gas Operator | Jun 2025 |
| 218 | McCulliss Resource Company Inc | Denver, CO 80202 | Oil & Gas Operator | Jun 1999 |
| 219 | McMurry Oil LLC | Denver, CO 80202 | Oil & Gas Operator | Dec 2004 |
| 220 | Medallion Exploration | Holladay, UT 84117 | Oil & Gas Operator | Dec 2015 |
| 221 | Memorial Production Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Jul 2025 |
| 222 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Jul 2025 |
| 223 | Merrion Oil & Gas Corp | Farmington, NM 87401 | Oil & Gas Operator | May 2025 |
| 224 | Michigan-Wisconsin Pipe Line Co | | Oil & Gas Operator | Dec 1983 |
| 225 | Midgard Energy Company | The Woodlands, TX 77380 | Oil & Gas Operator | Dec 2014 |
| 226 | Moncrief W A Jr | Fort Worth, TX 76102 | Oil & Gas Operator | May 2025 |
| 227 | MRD Operating LLC (Delaware) | Houston, TX 77010 | Oil & Gas Operator | Jul 2015 |
| 228 | Mull Drilling Company | Wichita, KS 67206 | Oil & Gas Operator | May 2025 |
| 229 | Mustang Resources LLC | Houston, TX 77256 | Oil & Gas Operator | May 2025 |
| 230 | MWJ Producing Company | Midland, TX 79701 | Oil & Gas Operator | Jul 1998 |
| 231 | Nance Petroleum Corporation | Billings, MT 59103-7168 | Oil & Gas Operator | Nov 2007 |
| 232 | National Energy Group, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Sep 2014 |
| 233 | Natural Gas Corp Of California | Vernal, UT 84078 | Oil & Gas Operator | Dec 1989 |
| 234 | Natural Gas Processing Company | Worland, WY 82401 | Oil & Gas Operator | Jun 2025 |
| 235 | Newport Oil Corporation | Clearwater, FL 33755 | Oil & Gas Operator | Jul 2011 |
| 236 | Noble Energy Inc | Midland, TX 79706 | Oil & Gas Operator | Jul 2025 |
| 237 | North Finn LLC | Casper, WY 82605 | Oil & Gas Operator | Jun 2025 |
| 238 | North Shore Exploration & Prod LLC | Broomfield, CO 80021 | Oil & Gas Operator | May 2025 |
| 239 | Northwest Exploration | | Oil & Gas Operator | Dec 1984 |
| 240 | Ocean Energy, Inc. | Houston, TX 77002 | Oil & Gas Operator | Aug 2003 |
| 241 | Okie Crude Company | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2025 |
| 242 | Omimex Petroleum Inc (De) | Fort Worth, TX 76120 | Oil & Gas Operator | Aug 2020 |
| 243 | Oryx Energy Company | Dallas, TX 75221 | Oil & Gas Operator | May 2002 |
| 244 | Ovintiv USA Inc. | Denver, CO 80202 | Oil & Gas Operator | Jul 2025 |
| 245 | Oxtex Inc | | Oil & Gas Operator | Oct 1989 |
| 246 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | Jul 2025 |
| 247 | P & M Petroleum Management LLC | Denver, CO 80202 | Oil & Gas Operator | Oct 2021 |
| 248 | P & P Producing Inc | Midland, TX 79702 | Oil & Gas Operator | Feb 2015 |
| 249 | P.O.&G. Operating, LLC | Houston, TX 77057 | Oil & Gas Operator | Jul 2025 |
| 250 | Pacific Enterprises Oil Co USA | Dallas, TX 75201 | Oil & Gas Operator | Feb 2001 |
| 251 | Pacific Transmission Supply | | Oil & Gas Operator | Dec 1987 |
| 252 | Patina Oil & Gas Corporation | Denver, CO 80202 | Oil & Gas Operator | May 2016 |
| 253 | Patrick Petroleum Co. | Jackson, MI 49201 | Oil & Gas Operator | Nov 1993 |
| 254 | Peakview Oil Company LLC | Denver, CO 80202 | Gas Operator | May 2025 |
| 255 | Pedco Resources Company | Tulsa, OK 74170 | Oil & Gas Operator | Mar 2008 |
| 256 | Pelican Dome Exploration | Harahan, LA 70123 | Oil & Gas Operator | Jun 1997 |
| 257 | Petra Petroleum Inc | Littleton, CO 80160-0319 | Oil & Gas Operator | Jun 2005 |
| 258 | Petral Exploration Inc LLC | Denver, CO 80217 | Oil & Gas Operator | May 2007 |
| 259 | Petro Search Exploration Corp | | Oil & Gas Operator | May 1993 |
| 260 | Petrogulf Corporation | Denver, CO 80202 | Oil & Gas Operator | Jul 2025 |
| 261 | Petrohawk Operating Company | Houston, TX 77056 | Oil & Gas Operator | Oct 2021 |
| 262 | Petroleum Corp Of Delaware The | | Oil & Gas Operator | May 1991 |
| 263 | Petroleum Inc | Wichita, KS 67202 | Oil & Gas Operator | Oct 2021 |
| 264 | Phillips Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Mar 2013 |
| 265 | Phoenix Resources Co | | Oil & Gas Operator | Jun 1984 |
| 266 | Pioneer Natural Resources USA Inc | Irving, TX 75039 | Oil & Gas Operator | Mar 2025 |
| 267 | Plains Petroleum Operating Co | Denver, CO 80202 | Oil & Gas Operator | Dec 2014 |
| 268 | Pogo Producing Company LLC | Houston, TX 77002 | Oil & Gas Operator | May 2025 |
| 269 | Polfam Exploration Co | Denver, CO 80204 | Oil & Gas Operator | Mar 2007 |
| 270 | Polumbus Corporation | Denver, CO 80202 | Oil & Gas Operator | Sep 1982 |
| 271 | Prenalta Corporation | Terrytown, NY 10591 | Oil & Gas Operator | Jan 1997 |
| 272 | Prime Operating Company | Houston, TX 77024 | Oil & Gas Operator | Jul 2025 |
| 273 | Qep Energy Company | Midland, TX 79701 | Oil & Gas Operator | Apr 2025 |
| 274 | Rainbow Oil Company | | Oil & Gas Operator | Aug 1999 |
| 275 | Ranch Oil Company | West Linn, OR 97068 | Oil & Gas Operator | Jun 2025 |
| 276 | Ranger Holdings Co | | Oil & Gas Operator | Jul 1993 |
| 277 | Rangeview Resources Operating Co | | Oil & Gas Operator | May 2025 |
| 278 | RB Operating Company | Shawnee, OK 74802-1488 | Oil & Gas Operator | Apr 2015 |
| 279 | Reading & Bates Petroleum | | Oil & Gas Operator | Apr 1989 |
| 280 | Reserve Oil & Gas Company | | Oil & Gas Operator | Jul 1981 |
| 281 | Reserve Operating Corp. | Houston, TX 77040 | Oil & Gas Operator | Jul 2025 |
| 282 | Riata Energy Inc | Oklahoma City, OK 73101 | Oil & Gas Operator | Apr 2008 |
| 283 | Richardson Operating Company | Denver, CO 80237 | Oil & Gas Operator | Jun 2025 |
| 284 | Rim Operating, Inc. | Englewood, CO 80112 | Oil & Gas Operator | Jul 2025 |
| 285 | Rio Blanco Energy, Inc. | Littleton, CO 80121 | Oil & Gas Operator | Oct 2002 |
| 286 | River Gas Corporation | Tuscaloosa, AL 35406-2233 | Gas Operator | Dec 2000 |
| 287 | Rme Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Nov 2016 |
| 288 | Robert Hawkins Inc | Kevin, MT 59454 | Oil & Gas Operator | May 2025 |
| 289 | Rock Creek Resources LLC | Englewood, CO 80112 | Oil & Gas Operator | Dec 2021 |
| 290 | Rocky Mountain Operating Co Inc | Littleton, CO 80121 | Oil & Gas Operator | Dec 2011 |
| 291 | Roemer Oil Company | Denver, CO 80202 | Oil & Gas Operator | Nov 1998 |
| 292 | Sabine Oil & Gas Corporation | Houston, TX 77002 | Oil & Gas Operator | Jul 2025 |
| 293 | Saga Petroleum LLC Of Colorado | Norman, OK 73072 | Oil & Gas Operator | Jul 2025 |
| 294 | Salt Creek Operating LLC | FT Morgan, CO 80701 | Oil & Gas Operator | Mar 2020 |
| 295 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 296 | Samson Oil & Gas USA Inc | Denver, CO 80202 | Oil & Gas Operator | May 2025 |
| 297 | Samson Resources Company LLC | Denver, CO 80202 | Oil & Gas Operator | Feb 2021 |
| 298 | San Marco Petroleum Inc | Denver, CO 80293 | Oil & Gas Operator | Jun 2025 |
| 299 | Sands-American Corp | | Oil & Gas Operator | Jan 1990 |
| 300 | Shell Rocky Mountain Production LLC | Pinedale, WY 82941 | Oil & Gas Operator | Dec 2008 |