| 501 | Petroleum Resource Management Corp | Denver, CO 80203 | Oil & Gas Operator | Jun 2025 |
| 502 | Petron Development Company | | Oil & Gas Operator | Oct 2020 |
| 503 | Petroshare Corporation | | Oil & Gas Operator | Jan 2024 |
| 504 | Petrox Resources Inc | Meeker, CO 81641 | Oil & Gas Operator | Jun 2025 |
| 505 | Phillips Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Mar 2013 |
| 506 | Phoenix Resources LLC | Longview, TX 75604 | Oil & Gas Operator | Jul 2022 |
| 507 | Piceance Energy LLC | | Oil & Gas Operator | May 2025 |
| 508 | Piceance Operating Company LLC | | Gas Operator | Oct 2006 |
| 509 | Piland Resources | | Oil & Gas Operator | Mar 2022 |
| 510 | Pine Ridge Oil & Gas LLC | | Oil & Gas Operator | Jul 2015 |
| 511 | Pineland Operating Company LLC | Dallas, TX 75231 | Oil & Gas Operator | Apr 2025 |
| 512 | Pintail Petroleum, LTD. | Wichita, KS 67202 | Oil & Gas Operator | Apr 2021 |
| 513 | Pioneer Natural Resources USA Inc | Irving, TX 75039 | Oil & Gas Operator | Mar 2025 |
| 514 | Pioneer Oil & Gas | South Jordan, UT 84095 | Oil & Gas Operator | Jan 2014 |
| 515 | Plains Exploration & Prod. Co. | Houston, TX 77002 | Oil & Gas Operator | Jul 2013 |
| 516 | Plains Petroleum Operating Co | Denver, CO 80202 | Oil & Gas Operator | Dec 2014 |
| 517 | Platinum Gas Properties LLC | | Gas Operator | Jun 2025 |
| 518 | Plug Nickel Oil Company Inc | | Oil & Gas Operator | May 2025 |
| 519 | Poc-I LLC | Casper, WY 82605 | Oil & Gas Operator | Jun 2025 |
| 520 | Polaris Production Opco LLC | | Oil & Gas Operator | Jun 2025 |
| 521 | Poncho Production Co | | Oil & Gas Operator | Jan 2022 |
| 522 | Pozo Resources, Inc | Houston, TX 77002 | Oil & Gas Operator | Jul 2025 |
| 523 | Prairie Operating Co LLC | | Oil & Gas Operator | Apr 2025 |
| 524 | Premium Oil Co | | Oil & Gas Operator | Dec 2015 |
| 525 | Presco Inc | The Woodlands, TX 77380 | Oil & Gas Operator | Oct 2020 |
| 526 | Prima Exploration, Inc. | Denver, CO 80206 | Oil & Gas Operator | Jun 2025 |
| 527 | Prime Operating Company | Houston, TX 77024 | Oil & Gas Operator | Jul 2025 |
| 528 | Private Oil Industries Inc | | Oil & Gas Operator | Feb 2004 |
| 529 | Production Management Inc | | Oil & Gas Operator | Jul 2021 |
| 530 | Pronghorn Operating LLC | | Oil Operator | Jan 2023 |
| 531 | Prospect Energy LLC | | Oil & Gas Operator | Jan 2024 |
| 532 | Prospective Investment & Trading Co., LTD., The | Tulsa, OK 74170-2320 | Oil & Gas Operator | Apr 2014 |
| 533 | Providence Operating LLC Dba Poco Operating | | Oil & Gas Operator | May 2025 |
| 534 | Prudent Resources LLC | Houston, TX 77042 | Oil & Gas Operator | Jul 2025 |
| 535 | Puckett-Warren Oil Co | | Oil & Gas Operator | Dec 2007 |
| 536 | QB Energy Operating LLC | | Oil & Gas Operator | May 2025 |
| 537 | Qep Energy Company | Midland, TX 79701 | Oil & Gas Operator | Apr 2025 |
| 538 | Qep Uinta Basin Inc | Salt Lake City, UT 84145-0601 | Oil & Gas Operator | Mar 2007 |
| 539 | Qualls Operating* R C | | Oil & Gas Operator | Mar 2005 |
| 540 | Quantum Resources Management LLC | Houston, TX 77010 | Oil & Gas Operator | Apr 2025 |
| 541 | Questar Expl. And Prod. Co. | Salt Lake Cty, UT 84145 | Oil & Gas Operator | Jul 2011 |
| 542 | Quicksilver Resources Inc | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2018 |
| 543 | Raisa II Operating LLC | | Oil & Gas Operator | Mar 2017 |
| 544 | Ram Oil And Gas, Inc. | Walsh, CO 81090 | Oil & Gas Operator | Jul 2025 |
| 545 | Rampart Energy Company | | Oil & Gas Operator | Dec 2024 |
| 546 | Rampike Resources LTD | Denver, CO 80202 | Oil Operator | May 2025 |
| 547 | Ramsey Property Management LLC | Oklahoma City, OK 73120-1955 | Oil & Gas Operator | Apr 2025 |
| 548 | Ranchers Exploration Partners LLC | | Oil & Gas Operator | Jan 2015 |
| 549 | Recovery Energy Inc | | Oil & Gas Operator | Jan 2014 |
| 550 | Red Hawk Petroleum LLC | | Oil & Gas Operator | May 2025 |
| 551 | Red Mesa Holdings/O&G LLC | | Oil & Gas Operator | Nov 2014 |
| 552 | Red Mountain Energy LLC | | Oil & Gas Operator | Sep 2017 |
| 553 | Red Mountain Resources LLC | | Oil & Gas Operator | Sep 2023 |
| 554 | Red Oak Operating, LLC | Magnolia, AR 71753 | Oil & Gas Operator | Dec 2024 |
| 555 | Red River Ranch Holdings LLC | | Gas Operator | Jan 2015 |
| 556 | Red Willow Production Company | | Oil & Gas Operator | May 2025 |
| 557 | Red Willow Production, LLC | Ignacio, CO 81137 | Oil & Gas Operator | Oct 2015 |
| 558 | Renegade Oil & Gas Company LLC | | Oil & Gas Operator | May 2025 |
| 559 | Resource Development Technology LLC | Morrison, CO 80465 | Oil & Gas Operator | Oct 2020 |
| 560 | Retamco Operating Inc | Red Lodge, MT 59068 | Oil & Gas Operator | May 2025 |
| 561 | Riata Energy Inc | Oklahoma City, OK 73101 | Oil & Gas Operator | Apr 2008 |
| 562 | Richardson Operating Company | Denver, CO 80237 | Oil & Gas Operator | Jun 2025 |
| 563 | Rim Operating, Inc. | Englewood, CO 80112 | Oil & Gas Operator | Jul 2025 |
| 564 | Rio Mesa Resources Inc | | Oil & Gas Operator | Jul 2022 |
| 565 | Ritchie Exploration, Inc. | Wichita, KS 67278 | Oil & Gas Operator | Mar 2025 |
| 566 | Riviera Drilling & Exploration Company | | Oil & Gas Operator | Sep 2013 |
| 567 | Rme Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Nov 2016 |
| 568 | Rock Creek Resources LLC | Englewood, CO 80112 | Oil & Gas Operator | Dec 2021 |
| 569 | Rocket Petroleum Company | | Oil & Gas Operator | Aug 2005 |
| 570 | Rockies Oil & Gas Inc | | Oil & Gas Operator | Dec 2015 |
| 571 | Rocky Mountain Operating Co Inc | Littleton, CO 80121 | Oil & Gas Operator | Dec 2011 |
| 572 | Rocky MTN Natural Gas LLC Adba Black Hills Energy | | Gas Operator | Dec 2003 |
| 573 | Rosetta Resources Operating LP | San Antonio, TX 78216 | Oil & Gas Operator | Jul 2025 |
| 574 | Rosewood Resources, Inc. | Dallas, TX 75201 | Oil & Gas Operator | Jul 2025 |
| 575 | Roughhouse Oil & Gas LLC | | Oil & Gas Operator | May 2025 |
| 576 | Rubicon Oil & Gas, LLC | Midland, TX 79701 | Oil & Gas Operator | Jul 2025 |
| 577 | Running Foxes Petroleum Inc. | Centennial, CO 80112 | Oil & Gas Operator | Mar 2025 |
| 578 | RWL Enterprises | | Oil & Gas Operator | Feb 2017 |
| 579 | S & D LLC | | Oil & Gas Operator | Aug 2022 |
| 580 | Saga Petroleum Limited Liability Co Of Co | | Oil & Gas Operator | Jun 2018 |
| 581 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 582 | Samson Oil Company | | Oil & Gas Operator | Feb 2001 |
| 583 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2025 |
| 584 | San Marco Petroleum Inc | Denver, CO 80293 | Oil & Gas Operator | Jun 2025 |
| 585 | Sand Hills Society | | Gas Operator | Oct 2009 |
| 586 | Sandlin Oil Corp | Dacono, CO 80514 | Oil & Gas Operator | Jun 2025 |
| 587 | Sandridge Energy Inc (Federal Wells Only) | | Oil & Gas Operator | Jun 2013 |
| 588 | Sandridge Exploration And Production LLC | Oklahoma City, OK 73104 | Oil & Gas Operator | Jul 2025 |
| 589 | Sawtooth Energy Partners LLC | | Oil & Gas Operator | Nov 2005 |
| 590 | Schmid Properties Inc | Hico, TX 76457 | Oil & Gas Operator | Jul 2025 |
| 591 | Schneider Energy Services Inc | | Oil & Gas Operator | Apr 2025 |
| 592 | Schreider & Company, Inc | | Oil & Gas Operator | Jun 2023 |
| 593 | Schuh And Associates | | Gas Operator | Feb 2000 |
| 594 | Schutz* Richard E | | Oil Operator | May 2025 |
| 595 | Scout Energy Management LLC | Dallas, TX 75240 | Oil & Gas Operator | Jul 2025 |
| 596 | Seeley Oil Company, LLC | Cortez, CO 81321 | Oil & Gas Operator | May 2025 |
| 597 | Setex Oil And Gas Company | Houston, TX 77002 | Oil & Gas Operator | Feb 2012 |
| 598 | SG Interests I LTD | Houston, TX 77007 | Oil & Gas Operator | Jun 2025 |
| 599 | Shawnee Oil Development Co Inc | | Oil & Gas Operator | May 2025 |
| 600 | Shepler & Thomas, Inc. | Edmond, OK 73013 | Oil & Gas Operator | Mar 2025 |