| 201 | Horizon Natural Resources, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Jan 2019 |
| 202 | Horizon Oil & Gas Co. | Dallas, TX 75221 | Oil & Gas Operator | Jan 2005 |
| 203 | HRB Operating Company, Inc. | Bridgeport, TX 76426 | Oil & Gas Operator | May 2025 |
| 204 | HS Resources, Inc. | Denver, CO 80202 | Oil & Gas Operator | Dec 2005 |
| 205 | Huber J M Corp | Edison, NJ 08837 | Oil & Gas Operator | May 2025 |
| 206 | Hugoton Energy Corporation | Oklahoma City, OK 73113 | Oil & Gas Operator | Dec 2019 |
| 207 | Hunter Oil Corporation | Gruver, TX 79040 | Gas Operator | May 2025 |
| 208 | Huntington Resources Inc | Tulsa, OK 74103 | Oil & Gas Operator | Oct 2006 |
| 209 | Hy-Tech, Inc. | Pampa, TX 79066 | Oil & Gas Operator | Feb 2017 |
| 210 | Intercoast Oil And Gas Company | Tulsa, OK 74136 | Oil & Gas Operator | Jun 1997 |
| 211 | J-Brex Company | Amarillo, TX 79101 | Oil & Gas Operator | May 2025 |
| 212 | JCB II Enterprises LLC | Perryton, TX 79070 | Oil & Gas Operator | Jun 2023 |
| 213 | JCR, Jr - Operating, Inc. | Amarillo, TX 79114 | Oil & Gas Operator | Apr 2022 |
| 214 | Jenex Operating Company Of Texas | Denver, CO 80209 | Oil & Gas Operator | Aug 2003 |
| 215 | Jilpetco, Inc. | Fort Worth, TX 76121 | Oil & Gas Operator | May 2025 |
| 216 | Jiro | Stinnett, TX 79083 | Oil & Gas Operator | May 2025 |
| 217 | Jones Energy LLC | Oklahoma City, OK 73134 | Oil & Gas Operator | Feb 2025 |
| 218 | Jones Energy, LTD. | Austin, TX 78746 | Oil & Gas Operator | Sep 2013 |
| 219 | JTL Operating Co Inc | Katy, TX 77450 | Oil & Gas Operator | May 2025 |
| 220 | K & D Operating Co. A | Gruver, TX 79040 | Oil & Gas Operator | Feb 2019 |
| 221 | K. Stewart Petroleum Corporation | Oklahoma City, OK 73103 | Oil & Gas Operator | Jun 2001 |
| 222 | K.M.A. Operating, Inc. | Graham, TX 76450 | Oil & Gas Operator | Aug 2003 |
| 223 | Kaiser-Francis Oil Company | Tulsa, OK 74121 | Oil & Gas Operator | May 2025 |
| 224 | Karper Oil & Gas Corporation | Graham, TX 76450 | Oil & Gas Operator | May 2025 |
| 225 | KCS Medallion Resources, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Nov 2018 |
| 226 | Kem Energy, Inc. | Katy, TX 77450 | Oil & Gas Operator | May 2025 |
| 227 | Kennedy & Mitchell, Inc. | Houston, TX 77084 | Oil & Gas Operator | Aug 2013 |
| 228 | Kerr-McGee Corporation | Dallas, TX 75380 | Oil & Gas Operator | Mar 2025 |
| 229 | Kerr-McGee Oil & Gas Onshore LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Feb 2017 |
| 230 | Kerr-McGee Oil & Gas Onshore LP | Houston, TX 77046 | Oil & Gas Operator | May 2025 |
| 231 | Key Energy Of Colorado, Inc. | Tulsa, OK 74103 | Oil & Gas Operator | Jun 2016 |
| 232 | Kile Production | Cypress, TX 77410 | Oil & Gas Operator | Aug 2014 |
| 233 | Kimball Production Co. | Houston, TX 77042 | Oil & Gas Operator | Jul 2002 |
| 234 | Kimbell Oil Company Of Texas | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2025 |
| 235 | Kimbrel Oil Corporation | Tulsa, OK 74114 | Oil & Gas Operator | May 2025 |
| 236 | King Operating Corporation | Fort Worth, TX 76147 | Oil & Gas Operator | May 2025 |
| 237 | Kodiak Oil & Gas Inc | Muenster, TX 76252 | Oil & Gas Operator | May 2025 |
| 238 | KRS Oil Company | Frisco, TX 75034 | Oil & Gas Operator | Apr 2020 |
| 239 | L & R Energy Corporation | Spearman, TX 79081 | Oil & Gas Operator | Nov 2014 |
| 240 | Laddex, LTD. | Amarillo, TX 79102 | Oil & Gas Operator | May 2025 |
| 241 | Laredo Petroleum Inc | Tulsa, OK 74120 | Oil & Gas Operator | Mar 2023 |
| 242 | Lasater & Co, Inc. | Spearman, TX 79081 | Oil & Gas Operator | May 2025 |
| 243 | Latigo (Texas), LLC | Tulsa, OK 74119 | Oil & Gas Operator | May 2025 |
| 244 | Latigo Petroleum LLC | Pampa, TX 79066 | Oil & Gas Operator | May 2025 |
| 245 | Latigo Petroleum Texas, LP | Houston, TX 77002 | Oil & Gas Operator | Feb 2009 |
| 246 | Latigo Petroleum, Inc. | Tulsa, OK 74119 | Oil & Gas Operator | Feb 2025 |
| 247 | Le Norman Operating LLC | Oklahoma City, OK 73142 | Oil & Gas Operator | Nov 2019 |
| 248 | Lease Holders Acquisitions LLC | Yukon, OK 73099 | Gas Operator | May 2025 |
| 249 | Lime Rock Resources II-A, L.P. | Houston, TX 77002 | Oil & Gas Operator | Feb 2025 |
| 250 | Linn Operating LLC | Houston, TX 77002 | Oil & Gas Operator | Jan 2019 |
| 251 | Linn Operating, Inc. | Houston, TX 77002 | Oil & Gas Operator | May 2017 |
| 252 | Lomak Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Aug 1998 |
| 253 | M E G G , Inc. | Borger, TX 79008 | Oil & Gas Operator | Sep 2003 |
| 254 | Magna Oil & Gas Corporation | Irving, TX 75017 | Oil & Gas Operator | Feb 2016 |
| 255 | Magnum Hunter Production, Inc. | Irving, TX 75014 | Oil & Gas Operator | Dec 2019 |
| 256 | Makar Production Company | Graham, TX 76450 | Oil & Gas Operator | May 2025 |
| 257 | Malson Oil Company | Crawford, OK 73638 | Oil & Gas Operator | Dec 2016 |
| 258 | Marexco, Inc. | Castle Rock, CO 80104 | Oil & Gas Operator | Jan 2025 |
| 259 | Maxus Exploration Company | Dallas, TX 75201 | Oil & Gas Operator | Jan 1995 |
| 260 | McDaniel Company, Inc., The | Dallas, TX 75230 | Oil & Gas Operator | May 2025 |
| 261 | McEna Inc | Tulsa, OK 74135 | Oil & Gas Operator | Jul 2005 |
| 262 | McGee, Tom Corporation | Booker, TX 79005 | Oil & Gas Operator | Feb 2025 |
| 263 | McKinney Operating Company | Canadian, TX 79014 | Gas Operator | May 2002 |
| 264 | McLeod, George L. Inc. | Houston, TX 77079 | Oil & Gas Operator | Sep 2002 |
| 265 | McNic Oil & Gas Midcontinent,Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Jul 1999 |
| 266 | Medallion Petroleum, Inc. | Tulsa, OK 74103 | Oil & Gas Operator | Jan 2015 |
| 267 | Medallion Production Company | Tulsa, OK 74103 | Oil & Gas Operator | May 1997 |
| 268 | Megg, L.P. | Borger, TX 79007 | Oil & Gas Operator | May 2025 |
| 269 | Merex Resources, Inc. | Amarillo, TX 79159 | Oil & Gas Operator | Sep 2019 |
| 270 | Mewbourne Oil Company | Tyler, TX 75711 | Oil & Gas Operator | May 2025 |
| 271 | Mge Resources, Inc. | Perryton, TX 79070 | Oil & Gas Operator | Feb 2025 |
| 272 | Midgard Energy Company | The Woodlands, TX 77380 | Oil & Gas Operator | Dec 2014 |
| 273 | Midstates Petroleum Company LLC | Tulsa, OK 74103 | Oil & Gas Operator | May 2018 |
| 274 | Mineral Development, Inc. | Dallas, TX 75231 | Oil & Gas Operator | Aug 1996 |
| 275 | Mitchell Ehrlich Oil & Gas, LLC | Austin, TX 78746 | Oil & Gas Operator | May 2025 |
| 276 | MMGL TXPH, LLC | Dallas, TX 75240 | Oil & Gas Operator | May 2025 |
| 277 | Mon Corp. | Pampa, TX 79066 | Oil & Gas Operator | May 2025 |
| 278 | Montgomery Petroleum, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Aug 2007 |
| 279 | MRR Oil Inc. | Perryton, TX 79070 | Oil & Gas Operator | Jun 2002 |
| 280 | Nadel And Gussman | Tulsa, OK 74103 | Oil & Gas Operator | May 2007 |
| 281 | National Energy Group, Inc. | Dallas, TX 75206 | Oil & Gas Operator | Sep 2014 |
| 282 | Natural Gas Anadarko Company | Perryton, TX 79070 | Oil & Gas Operator | May 2025 |
| 283 | New Arch Energy, LLC | Gruver, TX 79040 | Oil & Gas Operator | May 2025 |
| 284 | Nja Operating LLC | Perryton, TX 79070 | Oil & Gas Operator | May 2025 |
| 285 | O'Brien Energy Resources Corp | Portsmouth, NH 03801 | Oil & Gas Operator | May 2025 |
| 286 | O. H. M. Operating | Pampa, TX 79065 | Oil & Gas Operator | May 2025 |
| 287 | Oil Producers, Inc. Of Kansas | Wichita, KS 67206 | Oil & Gas Operator | May 2025 |
| 288 | Okla. Magic Circle Energy Corp. | Shawnee, OK 74801 | Oil & Gas Operator | Jul 2004 |
| 289 | Oklahoma Marlin Oil Corporation | Oklahoma City, OK 73113 | Oil & Gas Operator | Feb 2020 |
| 290 | Omar Operating Company | Midland, TX 79702 | Oil & Gas Operator | Sep 2013 |
| 291 | Oneok Exploration Company | Tulsa, OK 74102 | Oil & Gas Operator | Feb 2017 |
| 292 | Oneok Resources Company | Tulsa, OK 74102 | Oil & Gas Operator | Feb 2017 |
| 293 | Oringderff, Alma Oil Properties | Dallas, TX 75225 | Oil & Gas Operator | Mar 2012 |
| 294 | Oryx Energy Company | Dallas, TX 75221 | Oil & Gas Operator | May 2002 |
| 295 | Otc Petroleum Corporation | Nichols Hill, OK 73116 | Oil & Gas Operator | Mar 2015 |
| 296 | Overflow Energy, LLC | Booker, TX 79005 | Oil & Gas Operator | May 2025 |
| 297 | P. L. O. | Boerne, TX 78006 | Oil & Gas Operator | Jun 2016 |
| 298 | Pablo Energy II, LLC | Amarillo, TX 79105 | Oil & Gas Operator | Feb 2025 |
| 299 | Pablo Energy, Inc. | Pampa, TX 79065 | Oil & Gas Operator | Dec 2005 |
| 300 | Palo Duro Resources LLC | Perryton, TX 79070 | Oil & Gas Operator | May 2025 |