| 901 | Phoenix Operating LLC | Denver, CO 80237 | Oil & Gas Operator | May 2026 |
| 902 | Phoenix Production Company | Cody, WY 82414-3607 | Oil & Gas Operator | Oct 2023 |
| 903 | Phoenix Resources Co | | Oil & Gas Operator | Jun 1984 |
| 904 | Pine Haven Resources LLC | Boulder, CO 80305 | Oil Operator | Jun 2026 |
| 905 | Pinedale Energy Partners Operating LLC | Tulsa, OK 74105 | Oil & Gas Operator | Apr 2021 |
| 906 | Pinedale Investment Inc | Pinedale, WY 82941 | Oil & Gas Operator | Jun 2026 |
| 907 | Pioneer Exploration, LLC | Houston, TX 77090 | Oil & Gas Operator | Jun 2026 |
| 908 | Pioneer Natural Resources USA Inc | Irving, TX 75039 | Oil & Gas Operator | Mar 2026 |
| 909 | Pioneer Oil & Gas | South Jordan, UT 84095 | Oil & Gas Operator | Jan 2014 |
| 910 | Pittencrieff America Inc | Abilene, TX 79608 | Oil & Gas Operator | Feb 2003 |
| 911 | Pivonka Investments LLC | | Oil & Gas Operator | Jun 2026 |
| 912 | Plains Petroleum Operating Co | Denver, CO 80202 | Oil & Gas Operator | Dec 2014 |
| 913 | Planet Associates Inc | Denver, CO 80218 | Oil Operator | Dec 1994 |
| 914 | PML Operating LLC | | Oil Operator | May 2026 |
| 915 | Poc-I LLC | Casper, WY 82605 | Oil & Gas Operator | Jun 2026 |
| 916 | Pogo Producing Company LLC | Houston, TX 77002 | Oil & Gas Operator | May 2026 |
| 917 | Polfam Exploration Co | Denver, CO 80204 | Oil & Gas Operator | Mar 2007 |
| 918 | Polumbus Corporation | Denver, CO 80202 | Oil & Gas Operator | Sep 1982 |
| 919 | Powder Battalion Holdings LLC | Sheridan, WY 82801 | Gas Operator | Dec 2023 |
| 920 | Powder River Oil | Golden, CO 80401 | Oil & Gas Operator | Sep 2018 |
| 921 | Powder River Petroleum | Boerne, TX 78006 | Oil & Gas Operator | Dec 1998 |
| 922 | Powder River Royalty Inc | | Oil & Gas Operator | Dec 1986 |
| 923 | Powerline Energy Corporation | Arlington, TX 76015 | Oil & Gas Operator | Jul 2026 |
| 924 | PRB Oil & Gas Inc | Denver, CO 80202 | Gas Operator | Jul 2008 |
| 925 | Preferred Pipeline Corp. | Victoria, TX 77902 | Oil & Gas Operator | Jun 2026 |
| 926 | Prenalta Corporation | Terrytown, NY 10591 | Oil & Gas Operator | Jan 1997 |
| 927 | Pride Energy Company An Oklahoma GP | Tulsa, OK 74170 | Oil & Gas Operator | May 2026 |
| 928 | Prima Exploration, Inc. | Denver, CO 80206 | Oil & Gas Operator | Jun 2026 |
| 929 | Primary Fuels Inc | Midland, TX 79701-4410 | Oil & Gas Operator | Mar 1991 |
| 930 | Prime Operating Company | Midland, TX 79705 | Oil & Gas Operator | Jul 2026 |
| 931 | Principle Petroleum LLC | Dallas, TX 75313 | Oil Operator | May 2025 |
| 932 | Propel Energy Company | | Oil Operator | Oct 1991 |
| 933 | Prospective Invest & Trad Co LTD | Tulsa, OK 74170 | Oil & Gas Operator | Aug 2005 |
| 934 | Proven Petroleum, Inc. | Lakewood, CO 80228 | Oil & Gas Operator | May 2026 |
| 935 | Provident Resources LTD | | Oil & Gas Operator | Dec 1986 |
| 936 | Puma Petroleum I | | Oil & Gas Operator | Dec 1988 |
| 937 | Pure Petroleum LLC | Gillette, WY 82717 | Oil & Gas Operator | Aug 2011 |
| 938 | Purewest Resources Inc | Pinedale, WY 82941 | Oil & Gas Operator | May 2026 |
| 939 | Qep Energy Company | Midland, TX 79701 | Oil & Gas Operator | Apr 2026 |
| 940 | Qualmay Development LLC | Cody, WY 82414 | Oil & Gas Operator | Jun 2023 |
| 941 | Quest Operating LLC | Sheridan, WY 82801 | Gas Operator | Sep 2008 |
| 942 | Quicksilver Resources Inc | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2018 |
| 943 | Quinoco Petroleum Inc | | Oil & Gas Operator | Dec 1990 |
| 944 | Quintana Petroleum Corporation | Denver, CO 80265 | Oil & Gas Operator | Mar 2026 |
| 945 | Rael Resources LLC | Cowley, WY 82420 | Oil Operator | Jun 2026 |
| 946 | Rainbow Oil Company | | Oil & Gas Operator | Aug 1999 |
| 947 | Rainbow Resources, Inc. | Kilgore, TX 75663 | Oil & Gas Operator | Aug 2007 |
| 948 | Ramco Oil & Gas Inc | Midland, TX 79701 | Oil & Gas Operator | Nov 2006 |
| 949 | Ranch Oil Company | West Linn, OR 97068 | Oil & Gas Operator | Jun 2026 |
| 950 | Ranck Oil Company | Cut Bank, MT 59427 | Oil & Gas Operator | May 2026 |
| 951 | Ranger Holdings Co | | Oil & Gas Operator | Jul 1993 |
| 952 | Rangeview Resources Operating Co | | Oil & Gas Operator | Apr 2026 |
| 953 | Rathbun Roger | | Oil & Gas Operator | Dec 1993 |
| 954 | Rathpro Inc | Douglas, WY 82633 | Oil & Gas Operator | Feb 1994 |
| 955 | RB Operating Company | Shawnee, OK 74802-1488 | Oil & Gas Operator | Apr 2015 |
| 956 | RDG Oil & Gas LLC | Post Falls, ID 82854 | Oil & Gas Operator | Mar 2017 |
| 957 | Reading & Bates Petroleum | | Oil & Gas Operator | Apr 1989 |
| 958 | Red River Oil & Gas LLC | Cherry Hills, CO 80110 | Oil & Gas Operator | Feb 2025 |
| 959 | Red Rock Resources Corporation | Greenwood VIllage, CO 80111 | Oil & Gas Operator | May 2026 |
| 960 | Red Tiger Oil & Gas LLC | Gillette, WY 82718 | Oil & Gas Operator | May 2026 |
| 961 | Redbud E & P, Inc. | Giddings, TX 78942 | Oil & Gas Operator | Jul 2026 |
| 962 | Redstone Gas Partners LLC | Denver, CO 80202 | Gas Operator | Mar 2001 |
| 963 | Redstone Resources Inc | Newcastle, WY 82701 | Gas Operator | Dec 2010 |
| 964 | Reef Exploration Inc | Denver, CO 80202 | Oil & Gas Operator | Feb 2007 |
| 965 | Reliance Resources Inc | Houston, TX 77007 | Gas Operator | Jun 2012 |
| 966 | Remuda Energy Development LLC | Billings, MT 59104 | Oil & Gas Operator | Jun 2026 |
| 967 | Renor Exploration | Englewood, CO 80111 | Oil Operator | Feb 2001 |
| 968 | Renos Land & Minerals Company | Casper, WY 82601 | Oil & Gas Operator | Oct 2021 |
| 969 | Reserve Oil & Gas Company | | Oil & Gas Operator | Jul 1981 |
| 970 | Reserve Operating Corp. | Houston, TX 77040 | Oil & Gas Operator | Jul 2026 |
| 971 | Resolute Wyoming Inc | Denver, CO 80203 | Oil & Gas Operator | May 2018 |
| 972 | Resource Enterprises Inc | Salt Lake City, UT 84108 | Gas Operator | Dec 1990 |
| 973 | Resources Investment Corp | Denver, CO 80202 | Oil & Gas Operator | Sep 2018 |
| 974 | Reunion Energy Company | Houston, TX 77056 | Oil & Gas Operator | May 1996 |
| 975 | Rex Energy Rockies LLC | State College, PA 16801 | Oil & Gas Operator | May 2013 |
| 976 | Riata Energy, Inc. | Oklahoma City, OK 73101 | Oil & Gas Operator | Nov 2006 |
| 977 | Richardson Oil Company | San Antonio, TX 78216 | Oil & Gas Operator | Aug 2003 |
| 978 | Richardson Operating Company | Denver, CO 80237 | Oil & Gas Operator | May 2026 |
| 979 | Ridge Energy Partners LLC | Casper, WY 82601 | Oil Operator | Dec 2018 |
| 980 | Ridgeland Wyoming Inc | | Oil Operator | Dec 2014 |
| 981 | Rim Operating, Inc. | Englewood, CO 80112 | Oil & Gas Operator | Jul 2026 |
| 982 | Rio Blanco Energy, Inc. | Littleton, CO 80121 | Oil & Gas Operator | Oct 2002 |
| 983 | River City Resources, Inc. | Tulsa, OK 74119 | Oil & Gas Operator | Nov 1997 |
| 984 | River Gas Corporation | Tuscaloosa, AL 35406-2233 | Gas Operator | Dec 2000 |
| 985 | Rki Exploration & Production LLC | Tulsa, OK 74172 | Oil & Gas Operator | Jul 2026 |
| 986 | Rme Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Nov 2016 |
| 987 | Robert Hawkins Inc | Kevin, MT 59454 | Oil & Gas Operator | May 2026 |
| 988 | Rochelle Oil & Gas | Gillette, WY 82717 | Oil & Gas Operator | Mar 2024 |
| 989 | Rock Creek Resources LLC | Englewood, CO 80112 | Oil & Gas Operator | Dec 2021 |
| 990 | Rock Oil Corporation | Lawrence, KS 66046 | Oil Operator | Oct 2004 |
| 991 | Rock River Operating Inc | Laramie, WY 82070 | Oil & Gas Operator | Apr 2026 |
| 992 | Rockies Resources Holdings LLC | Lakewood, CO 80228 | Oil & Gas Operator | May 2026 |
| 993 | Rocky Mountain Gas Inc | Sheridan, WY 82801 | Gas Operator | Nov 2009 |
| 994 | Roemer Oil Company | Denver, CO 80202 | Oil & Gas Operator | Nov 1998 |
| 995 | Roff Operating Company LLC | Houston, TX 77002 | Oil & Gas Operator | Jul 2026 |
| 996 | Ronadero Company Inc | Roswell, NM BAD ADDR | Oil & Gas Operator | Dec 1996 |
| 997 | Rosa Petroleum | Evansville, WY 82636 | Oil Operator | Dec 1995 |
| 998 | Royal Oil LLC | Flower Mound, TX 75028 | Oil Operator | Dec 2015 |
| 999 | Royal Resources Exploration | | Oil & Gas Operator | Mar 1984 |
| 1000 | Ruby Drilling Company Inc | Gillette, WY 82718 | Oil Operator | Oct 2007 |