| 101 | Holwell Drilling Company | | Oil Operator | Sep 1992 |
| 102 | Home Petroleum Corp | Victoria, TX 77902 | Oil & Gas Operator | Apr 2026 |
| 103 | Hondo Oil & Gas | Houston, TX 77042 | Oil & Gas Operator | Oct 1995 |
| 104 | HRM Resources II, LLC | Denver, CO 80202 | Oil & Gas Operator | Jan 2022 |
| 105 | HRM Resources LLC | Denver, CO 80202 | Oil & Gas Operator | Aug 2015 |
| 106 | Hrubetz Oil Co. | Dallas, TX 75225 | Oil Operator | Sep 1986 |
| 107 | Hudson Group LLC | Casper, WY 82601 | Oil & Gas Operator | Jul 2025 |
| 108 | Hughes Oil Company Inc | Odessa, TX 79765 | Oil & Gas Operator | Feb 2004 |
| 109 | Hunt Oil Company | Dallas, TX 75201 | Oil & Gas Operator | Apr 2026 |
| 110 | Iks Operating | Upton, WY 82703 | Oil & Gas Operator | Jul 2013 |
| 111 | Indian Creek Resources Inc | Loveland, CO 80538 | Oil & Gas Operator | Dec 2024 |
| 112 | Infield Discovery LLC | Madison, MS 39110 | Oil & Gas Operator | Sep 2025 |
| 113 | Integrated Energy Inc | Houston, TX 77002 | Oil & Gas Operator | Aug 2003 |
| 114 | Integrated Petroleum Corporation | Denver, CO 80202 | Oil Operator | Jan 2010 |
| 115 | Integrity Oil & Gas | Golden, CO 80401 | Oil & Gas Operator | May 2011 |
| 116 | Kaiser-Francis Oil Company | Tulsa, OK 74121 | Oil & Gas Operator | Apr 2026 |
| 117 | Kara Enterprises Inc | Upton, WY 82730 | Oil Operator | Jul 2013 |
| 118 | Karlton Terry Oil Company | | Oil Operator | Jan 1991 |
| 119 | Kase Energy LLC | Roseville, MN 55113 | Oil Operator | Aug 2006 |
| 120 | Kem Ventures, LP | Katy, TX 77450 | Oil & Gas Operator | Jan 2026 |
| 121 | Kerr-McGee Corporation | Dallas, TX 75380 | Oil & Gas Operator | Feb 2026 |
| 122 | Kings X Oil Company LLC | Gillette, WY 82717 | Oil Operator | Aug 2016 |
| 123 | Kirkwood W C | Casper, WY 82602 | Oil & Gas Operator | May 2005 |
| 124 | Kissack Resources. LLC | | Oil & Gas Operator | Jan 2026 |
| 125 | Kissack Water & Oil Service Inc | Rozet, WY 82727 | Oil & Gas Operator | Feb 2026 |
| 126 | KWB Oil Property Management Inc | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2026 |
| 127 | L & J Operating Inc | Gillette, WY 82718 | Oil & Gas Operator | Aug 2016 |
| 128 | L & R Drilling Company | Belle Fourche, SD 57717 | Oil & Gas Operator | Dec 1999 |
| 129 | L R Company | Casper, WY 82602 | Oil & Gas Operator | Sep 2007 |
| 130 | Lagniappe Interest Inc | Evergreen, CO 80439 | Oil & Gas Operator | Jun 2006 |
| 131 | Lakota Partnership | Denver, CO 80202 | Oil Operator | Oct 1990 |
| 132 | Lario Oil & Gas Company | Odessa, TX 79762 | Oil & Gas Operator | Apr 2026 |
| 133 | Legacy Reserves Operating LP | Denver, CO 80201 | Oil & Gas Operator | Apr 2026 |
| 134 | Loil Oil LLC | Golden, CO 80402 | Oil & Gas Operator | Feb 2026 |
| 135 | Low D J | Littleton, CO 80127 | Oil Operator | Dec 1999 |
| 136 | M & K Oil Company LLC | Gillette, WY 82716 | Oil & Gas Operator | Feb 2026 |
| 137 | Marlin Oil Company LLC | Gillette, WY 82718 | Oil & Gas Operator | Mar 2023 |
| 138 | Marshall & Winston, Inc. | Midland, TX 79710 | Oil & Gas Operator | Feb 2026 |
| 139 | Materi Exploration Inc | Upton, WY 82730 | Oil Operator | Nov 2021 |
| 140 | Maxim Drilling & Expl Inc | Gillette, WY 82717 | Oil & Gas Operator | Jan 2026 |
| 141 | Maximus Operating, LTD. | Kilgore, TX 75663 | Oil & Gas Operator | Apr 2026 |
| 142 | McAdams Roux & Associates | Denver, CO 80202 | Oil & Gas Operator | Dec 1999 |
| 143 | McEna Inc | Tulsa, OK 74135 | Oil & Gas Operator | Jul 2005 |
| 144 | McGuire John C | Gillette, WY 82717 | Oil & Gas Operator | Oct 2005 |
| 145 | McO Resources Corporation | | Oil & Gas Operator | Feb 1986 |
| 146 | Merit Energy Company | Dallas, TX 75240 | Oil & Gas Operator | Apr 2026 |
| 147 | Meritage Energy Partners LLC | Denver, CO 80202 | Oil & Gas Operator | Dec 2005 |
| 148 | Mid-Con Energy Operating, LLC | Tulsa, OK 74136 | Oil & Gas Operator | Feb 2026 |
| 149 | Midgard Energy Company | The Woodlands, TX 77380 | Oil & Gas Operator | Dec 2014 |
| 150 | Mineral Resources & Engineering | Aladdin, WY 82710 | Oil Operator | Jul 1991 |
| 151 | Misahar Investments | Evergreen, CO 80439 | Oil Operator | Dec 1992 |
| 152 | MKM Services Inc | | Oil Operator | Mar 2026 |
| 153 | Montex Exploration | Sugarland, TX 77478 | Oil Operator | Apr 2003 |
| 154 | Nance Petroleum Corporation | Billings, MT 59103-7168 | Oil & Gas Operator | Nov 2007 |
| 155 | National Oil Company | Garden City, KS 67846 | Oil & Gas Operator | Jun 2024 |
| 156 | Natural Resource Corporation | Rock Springs, WY 82901 | Oil & Gas Operator | Sep 1983 |
| 157 | Neward Corporation | FT. Worth, TX 76102 | Oil & Gas Operator | Dec 1997 |
| 158 | North Finn LLC | Casper, WY 82605 | Oil & Gas Operator | Feb 2026 |
| 159 | Nova Energy Inc | Casper, WY 82601 | Oil & Gas Operator | Oct 2020 |
| 160 | O'Brien Energy Resources Corp | Portsmouth, NH 03801 | Oil & Gas Operator | Apr 2026 |
| 161 | Ocean Energy Inc | Houston, TX 77002 | Oil & Gas Operator | Aug 2003 |
| 162 | Oildigger Resources Fund L LLLP | Billings, MT 59101 | Oil & Gas Operator | Feb 2026 |
| 163 | Okie Crude Company | Tulsa, OK 74103 | Oil & Gas Operator | Jan 2026 |
| 164 | Olds Oil Company | Casper, WY 82604 | Oil Operator | Jun 1988 |
| 165 | Oryx Energy Company | Dallas, TX 75221 | Oil & Gas Operator | May 2002 |
| 166 | Osborn Heirs Company LTD | San Antonio, TX 78217 | Oil & Gas Operator | Dec 2025 |
| 167 | Oxford Exploration Company | Denver, CO 80237 | Oil & Gas Operator | Aug 1995 |
| 168 | Oxy USA Inc | Houston, TX 77046 | Oil & Gas Operator | Apr 2026 |
| 169 | P & M Petroleum Management LLC | Denver, CO 80202 | Oil & Gas Operator | Oct 2021 |
| 170 | P & P Producing Inc | Midland, TX 79702 | Oil & Gas Operator | Feb 2015 |
| 171 | P.O.&G. Operating, LLC | Houston, TX 77057 | Oil & Gas Operator | Apr 2026 |
| 172 | Pacific Enterprises Oil Co USA | Dallas, TX 75201 | Oil & Gas Operator | Feb 2001 |
| 173 | Pal LLC | Gillette, WY 82718 | Oil Operator | Dec 2019 |
| 174 | Parker & Parsley Producing LP | Midland, TX 79702 | Oil & Gas Operator | Oct 1997 |
| 175 | Pathfinder Energy Inc | Casper, WY 82605 | Oil & Gas Operator | May 2024 |
| 176 | Petro-Lewis Corp. | | Oil & Gas Operator | Feb 1994 |
| 177 | Petroleum Inc | Wichita, KS 67202 | Oil & Gas Operator | Oct 2021 |
| 178 | Petrorep Inc | | Oil Operator | Oct 1998 |
| 179 | Pine Haven Resources LLC | Boulder, CO 80305 | Oil Operator | Feb 2026 |
| 180 | Pioneer Oil & Gas | South Jordan, UT 84095 | Oil & Gas Operator | Jan 2014 |
| 181 | Plains Petroleum Operating Co | Denver, CO 80202 | Oil & Gas Operator | Dec 2014 |
| 182 | Planet Associates Inc | Denver, CO 80218 | Oil Operator | Dec 1994 |
| 183 | PML Operating LLC | | Oil Operator | Feb 2026 |
| 184 | Poc-I LLC | Casper, WY 82605 | Oil & Gas Operator | Feb 2026 |
| 185 | Polfam Exploration Co | Denver, CO 80204 | Oil & Gas Operator | Mar 2007 |
| 186 | Polumbus Corporation | Denver, CO 80202 | Oil & Gas Operator | Sep 1982 |
| 187 | Powder River Oil | Golden, CO 80401 | Oil & Gas Operator | Sep 2018 |
| 188 | Powder River Royalty Inc | | Oil & Gas Operator | Dec 1986 |
| 189 | Prenalta Corporation | Terrytown, NY 10591 | Oil & Gas Operator | Jan 1997 |
| 190 | Prima Exploration, Inc. | Denver, CO 80206 | Oil & Gas Operator | Feb 2026 |
| 191 | Prospective Invest & Trad Co LTD | Tulsa, OK 74170 | Oil & Gas Operator | Aug 2005 |
| 192 | Pure Petroleum LLC | Gillette, WY 82717 | Oil & Gas Operator | Aug 2011 |
| 193 | Quinoco Petroleum Inc | | Oil & Gas Operator | Dec 1990 |
| 194 | Quintana Petroleum Corporation | Denver, CO 80265 | Oil & Gas Operator | Mar 1998 |
| 195 | Ranch Oil Company | West Linn, OR 97068 | Oil & Gas Operator | Mar 2026 |
| 196 | Red Rock Resources Corporation | Greenwood VIllage, CO 80111 | Oil & Gas Operator | Feb 2026 |
| 197 | Red Tiger Oil & Gas LLC | Gillette, WY 82718 | Oil & Gas Operator | Jan 2026 |
| 198 | Resolute Wyoming Inc | Denver, CO 80203 | Oil & Gas Operator | May 2018 |
| 199 | Richardson Oil Company | San Antonio, TX 78216 | Oil & Gas Operator | Aug 2003 |
| 200 | Richardson Operating Company | Denver, CO 80237 | Oil & Gas Operator | Feb 2026 |