| 201 | Hughes Denny Offshore Expl Inc | | Oil & Gas Operator | Nov 1988 |
| 202 | Hughes Eastern Petroleum, Inc. | | Oil & Gas Operator | Apr 1993 |
| 203 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Mar 2025 |
| 204 | Hunt Petroleum (Aec), Inc. | Dallas, TX 75201 | Oil & Gas Operator | Nov 2008 |
| 205 | Hunt Petroleum Corporation | Dallas, TX 75201 | Oil & Gas Operator | Nov 2008 |
| 206 | Hydrocarbon MGMT., Inc. | | Oil & Gas Operator | Mar 1997 |
| 207 | Imc Exploration Co. | | Oil & Gas Operator | Oct 1986 |
| 208 | Imperial-American Energy,Inc. | | Oil & Gas Operator | Jul 1978 |
| 209 | Ingo Energy, LLC | | Oil & Gas Operator | Dec 2016 |
| 210 | Intercoast Oil And Gas Company | Tulsa, OK 74136 | Oil & Gas Operator | Jun 1997 |
| 211 | International Oil & Gas Corp. | | Oil & Gas Operator | Dec 1986 |
| 212 | Ip Petroleum Company, Inc. | Houston, TX 77210 | Oil & Gas Operator | Mar 2008 |
| 213 | James A. Whitson, Jr. | | Oil & Gas Operator | Apr 2016 |
| 214 | Jolen Operating Company | Oklahoma City, OK 73102 | Oil & Gas Operator | Dec 2024 |
| 215 | Jordan Oil & Gas Company | Healdsburg, CA 95448-1919 | Oil & Gas Operator | Mar 1995 |
| 216 | K-B Exploration Co. | Houston, TX 77057 | Oil & Gas Operator | Mar 2025 |
| 217 | Kaiser-Francis Oil Company | Tulsa, OK 74121 | Oil & Gas Operator | Mar 2025 |
| 218 | Kaneb Energy Company | | Oil & Gas Operator | Jan 1986 |
| 219 | Kaneb Operg Co. LTD. PTN. | | Oil & Gas Operator | Aug 1988 |
| 220 | Kash Oil And Gas, Inc | | Oil & Gas Operator | Oct 2020 |
| 221 | KCS Medallion Resources, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Nov 2018 |
| 222 | KCS Resources, Inc. | Houston, TX 77002 | Oil & Gas Operator | Feb 2009 |
| 223 | Kelley Oil Corp/Yuma Petroleum | | Gas Operator | Jun 1994 |
| 224 | Kelley Oil Corporation | Houston, TX 77002 | Oil & Gas Operator | Jan 2002 |
| 225 | Kelly H. Baxter | Austin, TX 78767 | Oil & Gas Operator | Nov 2006 |
| 226 | Kerr-McGee Rocky Mountain Corp | Denver, CO 80202 | Oil & Gas Operator | Jan 2007 |
| 227 | Key Operating Co., Inc. | Duncan, OK 73534-1284 | Oil & Gas Operator | Jan 2025 |
| 228 | Keystone Exploration, Inc | College Sta, TX 77845 | Oil & Gas Operator | Mar 2025 |
| 229 | Kilroy Co. Of Texas, Inc. | | Oil & Gas Operator | Jun 1991 |
| 230 | KJ Energy, LLC Of Delaware | | Oil & Gas Operator | Nov 2016 |
| 231 | Koch Gateway Pipeline Company | | Oil & Gas Operator | Feb 2001 |
| 232 | Kraker & Martin Energy, L.L.C. | Tulsa, OK 74136 | Oil & Gas Operator | Apr 2011 |
| 233 | Kriti Te Energy, Inc | Houston, TX 77079 | Oil & Gas Operator | Oct 2017 |
| 234 | La Intrastate Gas Co LLC | | Oil Operator | Apr 2004 |
| 235 | La. Land & Expl. Co. | | Oil & Gas Operator | Dec 2010 |
| 236 | La. Mining & Minerals, Inc. | | Oil & Gas Operator | Jul 2000 |
| 237 | Ladd Petroleum Corp. | Denver, CO 80202 | Oil & Gas Operator | Oct 2004 |
| 238 | Lake Racourci Gath Sys, LLC | | Oil Operator | May 2004 |
| 239 | Lasmo Energy Corporation | Tulsa, OK 74136 | Oil & Gas Operator | Jan 2024 |
| 240 | Laurel Operating Company, Inc. | Stillwater, OK 74074-3025 | Oil & Gas Operator | Jan 2025 |
| 241 | Lea Exploration, Inc. | | Oil & Gas Operator | Nov 1989 |
| 242 | Legacy Operating Company | | Oil & Gas Operator | Aug 1992 |
| 243 | LGS Exploration, Inc. | | Oil & Gas Operator | Jan 1991 |
| 244 | Linder Energy/La General Oil | | Oil & Gas Operator | Mar 1989 |
| 245 | Linder Oil Company | | Oil & Gas Operator | Apr 1985 |
| 246 | Linder Oil Company,A Partnership | Shreveport, LA 71136 | Oil & Gas Operator | Mar 2025 |
| 247 | Llog Expl. Co. | Metairie, LA 70005 | Oil & Gas Operator | Jan 2003 |
| 248 | Llog Exploration Company, LLC | | Oil & Gas Operator | Dec 2024 |
| 249 | Louisiana Gas Development Corp | | Oil & Gas Operator | Jan 2025 |
| 250 | Louisiana Intrastate Gas Corp. | | Oil Operator | Feb 1994 |
| 251 | Lynal, Inc. | | Oil & Gas Operator | Oct 1988 |
| 252 | Lyons Petroleum, Inc. | | Oil & Gas Operator | Oct 1988 |
| 253 | M & Z Engineering, Inc. | | Oil & Gas Operator | May 1998 |
| 254 | M. F. McCain, Inc. | | Oil & Gas Operator | Jul 1987 |
| 255 | Magnum Producing & Operating Co. | Corpus Chrsti, TX 78471 | Oil & Gas Operator | Jan 2004 |
| 256 | Main Energy, Inc. | Houston, TX 77079 | Oil & Gas Operator | May 2009 |
| 257 | Mandalay Oil & Gas, L.L.C. | | Oil & Gas Operator | May 2008 |
| 258 | Mannon L. Walters, Inc. | | Oil & Gas Operator | Jun 2024 |
| 259 | Map Drilling Company | | Oil & Gas Operator | Apr 2012 |
| 260 | Maple Gulf Coast Props. Corp. | | Oil & Gas Operator | Jun 1989 |
| 261 | Marion Corporation | | Oil & Gas Operator | Jan 2001 |
| 262 | Maritech Resources, LLC | | Oil & Gas Operator | May 2011 |
| 263 | Marsh Engineering, Inc. | | Oil & Gas Operator | Dec 1990 |
| 264 | Marshall Exploration, Inc. | | Oil & Gas Operator | Jun 1992 |
| 265 | Marshall Prod. & Energy Inc. | | Oil & Gas Operator | Jan 1992 |
| 266 | Marshland Exploration Company | | Oil & Gas Operator | May 2006 |
| 267 | Martin Exploration Co. | | Oil & Gas Operator | Apr 1986 |
| 268 | Masters Resources, L.L.C. | Houston, TX 77079 | Oil & Gas Operator | Dec 2008 |
| 269 | May Oil & Gas, L.L.C. | | Oil & Gas Operator | Dec 2013 |
| 270 | McCord Exploration Co. | | Oil & Gas Operator | Dec 1990 |
| 271 | McCord-Goodrich Oil Company | | Oil & Gas Operator | Oct 1991 |
| 272 | McCormick Operating Company | | Oil & Gas Operator | Mar 1984 |
| 273 | McMoran Exploration Company | | Oil & Gas Operator | May 1985 |
| 274 | McMoran Oil & Gas LLC | New Orleans, LA 70160 | Oil & Gas Operator | Oct 2021 |
| 275 | McMoran Production Co. | | Oil & Gas Operator | May 1985 |
| 276 | Medallion Production Company | Tulsa, OK 74103 | Oil & Gas Operator | May 1997 |
| 277 | Meridian Oil Inc. | Houston, TX 77210 | Oil & Gas Operator | Aug 1996 |
| 278 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Mar 2025 |
| 279 | Middle Bay Oil Company, Inc. | Houston, TX 77002 | Oil & Gas Operator | Apr 1998 |
| 280 | Middle Bay Production Co. Inc. | Houston, TX 77010 | Oil & Gas Operator | Sep 2014 |
| 281 | Midnight Drilling LLC | | Oil & Gas Operator | Jan 2016 |
| 282 | Mobil E&P North America Inc. | | Oil & Gas Operator | Jan 1994 |
| 283 | Mobil Oil E & P Southeast Inc | | Oil & Gas Operator | Sep 2013 |
| 284 | Moco Operating Company | | Oil & Gas Operator | Mar 2002 |
| 285 | Moran Exploration, Inc. | | Oil & Gas Operator | Jan 1985 |
| 286 | Mosbacher Energy Company | Houston, TX 77002 | Oil & Gas Operator | Mar 2025 |
| 287 | Mullen Exploration Inc | | Oil & Gas Operator | Dec 2002 |
| 288 | Mullins & Prichard | | Oil & Gas Operator | May 1992 |
| 289 | Murphy Exp & Prod Co.-USA | | Oil & Gas Operator | May 2014 |
| 290 | Murphy Exploration & Prod. Co. | Houston, TX 77094 | Oil & Gas Operator | Jun 2011 |
| 291 | Mustang Energy L C | | Oil & Gas Operator | Jan 2013 |
| 292 | MW Petroleum Corporation | Houston, TX 77056 | Oil & Gas Operator | Mar 2015 |
| 293 | Nerco Oil & Gas, Inc. | | Oil & Gas Operator | Dec 1996 |
| 294 | Neuhoff Oil & Gas Corp. | | Oil & Gas Operator | Dec 1986 |
| 295 | Newfield Exploration Company | The Woodlands, TX 77380 | Oil & Gas Operator | Jun 2017 |
| 296 | Noble Energy Inc | Midland, TX 79706 | Oil & Gas Operator | Mar 2025 |
| 297 | Nomeco Oil & Gas Co. | Jackson, MI 49204 | Oil & Gas Operator | Dec 1994 |
| 298 | Norcen Explorer, Inc. | Houston, TX 77079 | Oil & Gas Operator | May 1998 |
| 299 | North American Royalties, Inc. | Chattanooga, TN 37408 | Oil & Gas Operator | Oct 2001 |
| 300 | Northern Michigan Expl Co | | Oil & Gas Operator | Jul 1990 |