| 201 | Forcenergy Inc | Miami, FL 33129 | Oil & Gas Operator | Mar 2015 |
| 202 | Foree R L | Dallas, TX 75225 | Oil & Gas Operator | Aug 2001 |
| 203 | Forest Oil Permian Corporation | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 204 | Forestar Petroleum Corporation | Denver, CO 80202 | Oil & Gas Operator | May 2017 |
| 205 | Frank Louis L | Kingsville, TX 78364 | Oil & Gas Operator | Aug 2003 |
| 206 | Frickey Investment MGT Co LLC | Lakewood, CO 80215 | Oil & Gas Operator | Jun 2026 |
| 207 | Fuel Resources Development Co | Denver, CO 80202 | Oil & Gas Operator | Feb 1994 |
| 208 | H & H Star Energy Inc | Traverse City, MI 49684 | Oil & Gas Operator | Aug 2016 |
| 209 | H & M Oil Producers | Littleton, CO 80160 | Oil & Gas Operator | Apr 2000 |
| 210 | H & R Well Services, Inc. | FT Morgan, CO 80701 | Oil & Gas Operator | Apr 2015 |
| 211 | H C M Energy LLC | Billings, MT 59102 | Oil Operator | Jul 2003 |
| 212 | Hamon Jake L | Dallas, TX 75201-3902 | Oil & Gas Operator | Nov 1997 |
| 213 | Harper Oil Co. | Denver, CO 80217 | Oil & Gas Operator | Mar 2026 |
| 214 | Harrell Oil Company LLC | Ardmore, OK 73402 | Oil Operator | Jan 2025 |
| 215 | Harvey E Yates Company | Roswell, NM 88202 | Oil & Gas Operator | Feb 2015 |
| 216 | Havoco Inc | Newcastle, WY 82701 | Oil & Gas Operator | Aug 2005 |
| 217 | Hawks Industries Inc | Casper, WY 82601 | Oil & Gas Operator | Jun 1993 |
| 218 | Headington Oil Company, L.P. | Dallas, TX 75231 | Oil & Gas Operator | Mar 2008 |
| 219 | Heartland Energy Company | Big Horn, WY 82833 | Gas Operator | Jun 2012 |
| 220 | Helis Oil & Gas Company LLC Estate | New Orleans, LA 70130 | Oil & Gas Operator | Jul 2022 |
| 221 | Henderson Petroleum Corp | San Angelo, TX 76906 | Oil & Gas Operator | Jul 2013 |
| 222 | Hi-Pro Production | Gillette, WY 82717 | Gas Operator | Nov 2003 |
| 223 | High Plains Gas LLC | Gillette, WY 82717 | Gas Operator | Aug 2014 |
| 224 | Hilcorp Energy Company | Houston, TX 77208 | Oil & Gas Operator | Jul 2026 |
| 225 | HNG Oil Company | | Oil & Gas Operator | Jun 1987 |
| 226 | Hodge T F | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 2007 |
| 227 | Holly Energy Inc | | Oil Operator | Apr 1983 |
| 228 | Home Petroleum Corp | Victoria, TX 77902 | Oil & Gas Operator | Jul 2026 |
| 229 | Hondo Oil & Gas | Houston, TX 77042 | Oil & Gas Operator | Oct 1995 |
| 230 | Houston Oil And Minerals | | Oil & Gas Operator | Oct 1993 |
| 231 | Howell Petroleum Corporation | Houston, TX 77251 | Oil & Gas Operator | Oct 2015 |
| 232 | HRM Resources II, LLC | Denver, CO 80202 | Oil & Gas Operator | Mar 2026 |
| 233 | HRM Resources LLC | Denver, CO 80202 | Oil & Gas Operator | Aug 2015 |
| 234 | Hrubetz Oil Co. | Dallas, TX 75225 | Oil Operator | Sep 1986 |
| 235 | Huber J M Corp | Edison, NJ 08837 | Oil & Gas Operator | Jul 2026 |
| 236 | Hudson Group LLC | Casper, WY 82601 | Oil & Gas Operator | Jul 2025 |
| 237 | Hugoton Energy Corporation | Oklahoma City, OK 73113 | Oil & Gas Operator | Dec 2019 |
| 238 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Jul 2026 |
| 239 | Hydrocarbon Management, Inc. | San Antonio, TX 78216 | Oil & Gas Operator | Dec 1996 |
| 240 | J & J Production LLC | Worland, WY 82401 | Oil Operator | Dec 2025 |
| 241 | Jade Resources Inc | Englewood, CO 80112 | Oil Operator | Jul 1998 |
| 242 | Jay Management Company LLC | Houston, TX 77057 | Oil & Gas Operator | Jul 2026 |
| 243 | Jenex Petroleum Corporation | The Woodlands, TX 77380 | Oil & Gas Operator | Jul 2026 |
| 244 | Jims Water Service Inc | Gillette, WY 82717 | Oil & Gas Operator | Oct 2016 |
| 245 | JM Cox Resources LP | Midland, TX 79702 | Oil & Gas Operator | Apr 2019 |
| 246 | JN Exploration & Production | Billings, MT 59103-0159 | Oil & Gas Operator | Apr 2001 |
| 247 | Joemar Wyoming Operating LLC | | Oil & Gas Operator | May 2026 |
| 248 | Juniper Petroleum Corporation | | Oil & Gas Operator | Aug 1983 |
| 249 | Justice Oil & Gas LLC | Gillette, WY 82716 | Oil & Gas Operator | May 2026 |
| 250 | Jva Operating Company | Midland, TX 79710 | Oil & Gas Operator | Oct 2021 |
| 251 | K & W Oil Company | MT Carmel, IL 62830 | Oil & Gas Operator | May 2013 |
| 252 | Kaiser Energy Inc | Denver, CO 80202 | Oil & Gas Operator | Dec 1990 |
| 253 | Kaiser-Francis Oil Company | Tulsa, OK 74121 | Oil & Gas Operator | Jul 2026 |
| 254 | Kauffman K P Company Inc | Denver, CO 80202 | Oil & Gas Operator | Mar 1996 |
| 255 | KCS Medallion Resources, Inc. | Tulsa, OK 74136 | Oil & Gas Operator | Nov 2018 |
| 256 | Keas Production Company LLC | Estes Park, CO 80517 | Oil Operator | Apr 2026 |
| 257 | Keith Walker O & G Co LLC | | Oil Operator | Jun 2026 |
| 258 | Kelly Operating Company | | Oil & Gas Operator | Oct 1991 |
| 259 | Kem Ventures, LP | Katy, TX 77450 | Oil & Gas Operator | May 2026 |
| 260 | Kenai Oil & Gas Inc | | Oil & Gas Operator | Jun 1987 |
| 261 | Kennedy & Mitchell | Woodward, OK 73802 | Oil & Gas Operator | Dec 1988 |
| 262 | Kennedy George C | Upton, WY 82730 | Oil & Gas Operator | Oct 2018 |
| 263 | Kennedy Oil | Gillette, WY 82716 | Oil & Gas Operator | May 2026 |
| 264 | Kerr-McGee Corporation | Dallas, TX 75380 | Oil & Gas Operator | Feb 2026 |
| 265 | Kestrel Energy Inc | Lakewood, CO 80401 | Oil & Gas Operator | Jan 2008 |
| 266 | Kirkwood W C | Casper, WY 82602 | Oil & Gas Operator | May 2005 |
| 267 | Kissack Resources. LLC | | Oil & Gas Operator | Jun 2026 |
| 268 | Kissack Water & Oil Service Inc | Rozet, WY 82727 | Oil & Gas Operator | Jun 2026 |
| 269 | Kissinger Petroleum Corp | | Oil & Gas Operator | Nov 1983 |
| 270 | Klabzuba Oil & Gas Inc | Denver, CO 80202 | Oil & Gas Operator | Aug 2012 |
| 271 | L & J Operating Inc | Gillette, WY 82718 | Oil & Gas Operator | Aug 2016 |
| 272 | L & R Drilling Company | Belle Fourche, SD 57717 | Oil & Gas Operator | Dec 1999 |
| 273 | L B Industries Inc | Englewood, CO 80112 | Oil & Gas Operator | Jun 2003 |
| 274 | Ladd & Lukowicz | | Oil & Gas Operator | May 1983 |
| 275 | Laguna Petroleum Company | Casper, WY 82601 | Oil & Gas Operator | Dec 1982 |
| 276 | Lance Oil & Gas Company Inc | Kirtland, NM 87417 | Oil & Gas Operator | Mar 2013 |
| 277 | Langley Energy | Euless, TX 76040 | Gas Operator | Jan 2016 |
| 278 | Lario Oil & Gas Company | Odessa, TX 79762 | Oil & Gas Operator | Jul 2026 |
| 279 | Lasmo Energy Corporation | Tulsa, OK 74136 | Oil & Gas Operator | Jan 2024 |
| 280 | Lear Petroleum Exploration | | Oil & Gas Operator | Jul 2013 |
| 281 | Leclair-Westwood Inc | | Oil & Gas Operator | Mar 1982 |
| 282 | Legacy Reserves Operating LP | Denver, CO 80201 | Oil & Gas Operator | Jul 2026 |
| 283 | Levinson Partners Corporation | Denver, CO 80202 | Oil & Gas Operator | Jul 1995 |
| 284 | Liberty Resources Management Co LLC | Denver, CO 80202 | Oil & Gas Operator | May 2026 |
| 285 | Loil Oil LLC | Golden, CO 80402 | Oil & Gas Operator | Mar 2026 |
| 286 | Long Trust The | Kilgore, TX 75663 | Oil & Gas Operator | Aug 2008 |
| 287 | Loral Operating LLC | Sheridan, WY 82801 | Gas Operator | Apr 2011 |
| 288 | Louisiana Land & Exploration Co. | Houston, TX 77210 | Oil & Gas Operator | Sep 2013 |
| 289 | Low D J | Littleton, CO 80127 | Oil Operator | Dec 1999 |
| 290 | Lowry Exploration Inc | Tulsa, OK 74119 | Oil & Gas Operator | Apr 2026 |
| 291 | Luff Exploration | Denver, CO 80203 | Oil & Gas Operator | Dec 2006 |
| 292 | M & K Oil Company LLC | Gillette, WY 82716 | Oil & Gas Operator | May 2026 |
| 293 | Mack Energy Corporation | Artesia, NM 88211 | Oil & Gas Operator | May 2026 |
| 294 | Main Energy, Inc. | Houston, TX 77079 | Oil & Gas Operator | May 2009 |
| 295 | Majestic Petroleum Operations Inc | Story, WY 82842 | Gas Operator | Mar 2007 |
| 296 | Mallon Oil Company | Denver, CO 80202 | Oil & Gas Operator | Jun 2005 |
| 297 | Manx Oil Corporation | Casper, WY 82601 | Oil & Gas Operator | Jun 2010 |
| 298 | Marathon Oil Company | Houston, TX 77252 | Oil & Gas Operator | May 2026 |
| 299 | Marlin Oil Company LLC | Gillette, WY 82718 | Oil & Gas Operator | Mar 2023 |
| 300 | Marmik Oil Company | El Dorado, AR 71730 | Oil & Gas Operator | Jan 2015 |