| 601 | Philcon Development Co. | Amarillo, TX 79101 | Oil & Gas Operator | Sep 2014 |
| 602 | Pioneer Natural Res. USA, Inc. | Spring, TX 77389 | Oil & Gas Operator | Apr 2026 |
| 603 | Plains Petroleum Operating Co | Denver, CO 80202 | Oil & Gas Operator | Dec 2014 |
| 604 | Poblano Energy LLC | Houston, TX 77024-2217 | Oil & Gas Operator | Feb 2026 |
| 605 | Pogo Panhandle 2004, L.P. | Houston, TX 77002 | Oil & Gas Operator | Oct 2017 |
| 606 | Pogo Producing Company LLC | Houston, TX 77002 | Oil & Gas Operator | Feb 2026 |
| 607 | Polaris Energy Dev Co | Tulsa, OK 74135 | Oil & Gas Operator | Apr 2000 |
| 608 | Post Oak Oil Company | Oklahoma City, OK 73112 | Oil & Gas Operator | Jul 2013 |
| 609 | Post Petroleum Company | Oklahoma City, OK 73116 | Oil & Gas Operator | Aug 2013 |
| 610 | PRDJ Cockrum Enterprises, Inc. | Okemah, OK 74859-5126 | Oil & Gas Operator | Mar 2022 |
| 611 | Premier Resources LTD | Denver, CO 80237 | Oil & Gas Operator | Jul 2002 |
| 612 | Prentice, Napier & Green, Inc. | Oklahoma City, OK 73142 | Oil & Gas Operator | Feb 2026 |
| 613 | Pride Energy Company | Tulsa, OK 74170 | Oil & Gas Operator | Apr 2026 |
| 614 | Primary Natural Resources III LLC | Tulsa, OK 74136-6351 | Oil & Gas Operator | Jan 2026 |
| 615 | Primary Natural Resources Inc. | Tulsa, OK 74136-6351 | Oil & Gas Operator | Mar 2023 |
| 616 | Prime Energy Corp | Charleston, WV 25301-1707 | Oil & Gas Operator | Sep 2015 |
| 617 | Prime Operating Company | Midland, TX 79705 | Oil & Gas Operator | Apr 2026 |
| 618 | Primexx Operating Corporation | Dallas, TX 75206 | Oil & Gas Operator | Mar 2024 |
| 619 | Princess Three Corporation | Henderson, TX 75653 | Oil & Gas Operator | Apr 2020 |
| 620 | Princess Three Operating, LLC | Henderson, TX 75653 | Oil & Gas Operator | Apr 2026 |
| 621 | Pringle Operating Co. | Tulsa, OK 74103 | Oil & Gas Operator | Aug 2015 |
| 622 | Prize Operating Company | Grapevine, TX 76051 | Oil & Gas Operator | Aug 2016 |
| 623 | Producers Oil Company | Tulsa, OK 74103 | Oil & Gas Operator | Jan 2007 |
| 624 | Proex Energy Management, L.L.C. | Spring, TX 77386 | Oil & Gas Operator | Apr 2026 |
| 625 | Protege Energy LLC | Tulsa, OK 74135 | Oil & Gas Operator | Jan 2018 |
| 626 | Proven Reserves Management, Inc. | Dallas, TX 75370 | Oil & Gas Operator | Jan 2026 |
| 627 | PXP Gulf Coast Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 628 | Qep Energy Company | Midland, TX 79701 | Oil & Gas Operator | Jan 2026 |
| 629 | Quail Creek Oil Corporation | Houston, TX 77024 | Oil & Gas Operator | Apr 2026 |
| 630 | Quail Creek Petro MGMT Corp | Oklahoma City, OK 73134 | Oil & Gas Operator | Aug 2013 |
| 631 | Quail Oil & Gas LC | Garden City, KS 67846 | Oil & Gas Operator | Jan 2026 |
| 632 | Quantum Resources Management LLC | Houston, TX 77010 | Oil & Gas Operator | Jan 2026 |
| 633 | Questa Energy Corporation | Amarillo, TX 79159 | Oil & Gas Operator | Apr 2026 |
| 634 | Questa Oil & Gas Co. | Tulsa, OK 74170 | Oil & Gas Operator | Mar 2015 |
| 635 | R & A Moore, Inc. | Cleburne, TX 76033 | Oil & Gas Operator | Apr 2026 |
| 636 | R E Blaik Inc | Edmond, OK 73013-6675 | Oil & Gas Operator | Feb 2026 |
| 637 | R3 Resources Operating Corporation | Denver, CO 80222 | Oil & Gas Operator | Jan 2026 |
| 638 | Rama Operating Company Inc | Stafford, KS 67578 | Oil & Gas Operator | Feb 2026 |
| 639 | Ramco Energy Corporation | FT. Lauderdale, FL 33312 | Oil & Gas Operator | Dec 2008 |
| 640 | Ramco Oil & Gas Inc | Midland, TX 79701 | Oil & Gas Operator | Nov 2006 |
| 641 | Ramsey Engineering Inc | Oklahoma City, OK 73118 | Oil & Gas Operator | Apr 1993 |
| 642 | Ramsey Nichols Operating Company LLC | Oklahoma City, OK 73120-1955 | Oil & Gas Operator | Feb 2026 |
| 643 | Ramsey Property Management LLC | Oklahoma City, OK 73120 | Oil & Gas Operator | Jan 2026 |
| 644 | Ramsey Property MGMT Inc | Oklahoma City, OK 73120-1955 | Oil & Gas Operator | Mar 2019 |
| 645 | Range Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Sep 2021 |
| 646 | Range Production Company, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Feb 2026 |
| 647 | Rasmussen, Hal J. Operating, Inc | Midland, TX 79701 | Oil & Gas Operator | Apr 2009 |
| 648 | Ray G H Oil Company | Chickasha, OK 73023-0650 | Oil Operator | Feb 2010 |
| 649 | Raydon Exploration, Inc. | Oklahoma City, OK 73118 | Oil & Gas Operator | Apr 2026 |
| 650 | RB Operating Company | Shawnee, OK 74802-1488 | Oil & Gas Operator | Apr 2015 |
| 651 | Redland Resources LLC | Oklahoma City, OK 73127 | Oil & Gas Operator | Feb 2026 |
| 652 | Redline Energy LLC | Dover, OK 73734 | Oil & Gas Operator | Feb 2026 |
| 653 | Redstone Oil & Gas Company | Dallas, TX 75225 | Oil & Gas Operator | Jan 2020 |
| 654 | Reeder Energy Operating LLC | Dallas, TX 75206-4085 | Oil & Gas Operator | Dec 2021 |
| 655 | Remnant Energy, Inc. | Perryton, TX 79070 | Oil & Gas Operator | Apr 2026 |
| 656 | Republic Energy Inc. | Decatur, TX 76234 | Oil & Gas Operator | Dec 2016 |
| 657 | Republic Resources Corporation | Oklahoma City, OK 73102-3081 | Oil & Gas Operator | May 2021 |
| 658 | Resource Dev Technology LLC | Morrison, CO 80465-5020 | Oil & Gas Operator | Jan 2017 |
| 659 | Resource Oil And Gas, LLC | Oklahoma City, OK 73114 | Oil & Gas Operator | Apr 2026 |
| 660 | Revelation Resources | Cypress, TX 77410-2578 | Oil & Gas Operator | Jan 2026 |
| 661 | Ricks Exploration Co | Oklahoma City, OK 73112 | Oil & Gas Operator | Mar 2015 |
| 662 | Riviera Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | Feb 2026 |
| 663 | RKK Production Company | Mustang, OK 73064 | Oil & Gas Operator | Feb 2026 |
| 664 | RMS Monte Christo, LLC | Snowmass VLG., CO 81615 | Oil & Gas Operator | Mar 2023 |
| 665 | Ross Curtis | Ada, OK 74820-1354 | Oil & Gas Operator | Feb 2012 |
| 666 | Royal Petroleum | Baytown, TX 77521 | Oil & Gas Operator | Aug 2003 |
| 667 | RTC Resources, LLP | Weatherford, OK 73096 | Oil & Gas Operator | Apr 2026 |
| 668 | Rupe Oil Company Inc | Wichita, KS 67278 | Oil & Gas Operator | Dec 2025 |
| 669 | Ryan Petroleum Corp | Oklahoma City, OK 73102-9024 | Oil & Gas Operator | Aug 1994 |
| 670 | S & J Operating Company | Wichita Falls, TX 76301 | Oil & Gas Operator | Mar 2015 |
| 671 | S R W Oil | Laverne, OK 73848 | Oil & Gas Operator | Sep 2025 |
| 672 | Sabre Operating, Inc. | Wichita Falls, TX 76308 | Oil & Gas Operator | Apr 2026 |
| 673 | Sage Drilling Co Inc | Wichita, KS 67202 | Oil & Gas Operator | Nov 1998 |
| 674 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 675 | Samis Oil Company, Inc. | Oklahoma City, OK 73156 | Oil & Gas Operator | Sep 2000 |
| 676 | Samson Gas Producing Company | Tulsa, OK 74103 | Oil & Gas Operator | May 2001 |
| 677 | Samson Hydrocarbons Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2016 |
| 678 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Jan 2026 |
| 679 | Sand Point Production Inc | Oklahoma City, OK 73172 | Oil & Gas Operator | Jan 2026 |
| 680 | Sandlot Oil & Gas LLC | Gruver, TX 79040 | Oil & Gas Operator | Apr 2026 |
| 681 | Sandridge Exploration And Production LLC | Oklahoma City, OK 73104 | Oil & Gas Operator | Apr 2026 |
| 682 | Sanford Casondra | Ada, OK 74820-4460 | Oil & Gas Operator | May 2013 |
| 683 | Santa Fe Minerals, Inc. | Dallas, TX 75240 | Oil & Gas Operator | Sep 2013 |
| 684 | Saqus Oil Co | Oklahoma City, OK 73107 | Oil & Gas Operator | May 2001 |
| 685 | Scana Exploration Company | Houston, TX 77002 | Oil & Gas Operator | Dec 1999 |
| 686 | Scana Petroleum Resources Inc | Houston, TX 77002 | Oil & Gas Operator | Jun 2013 |
| 687 | Scana Production Company | Houston, TX 77002 | Oil & Gas Operator | Mar 2005 |
| 688 | Scarth Oil & Gas Co | Amarillo, TX 79101 | Oil & Gas Operator | Feb 1999 |
| 689 | Schmid Properties, Inc. | Hico, TX 76457 | Oil & Gas Operator | Apr 2026 |
| 690 | Scout Energy Management LLC | Dallas, TX 75240 | Oil & Gas Operator | Apr 2026 |
| 691 | SCS Newton Oil LLC | Perryton, TX 79070 | Oil & Gas Operator | Apr 2026 |
| 692 | Seagull Energy E & P Inc | Houston, TX 77002 | Oil & Gas Operator | Jan 2015 |
| 693 | Seagull Mid-South Inc | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 694 | Seagull Midcon Inc. | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 695 | Search Drilling Company | Houston, TX 77010 | Oil & Gas Operator | Feb 2001 |
| 696 | Sec Production Inc | Edmond, OK 73013-3709 | Oil & Gas Operator | Feb 2026 |
| 697 | Seneca Oil Company | Tulsa, OK 74121-1518 | Oil & Gas Operator | Jan 2015 |
| 698 | Sensor Oil & Gas, Inc. | Duncan, OK 73534 | Oil & Gas Operator | May 2013 |
| 699 | Service Drilling Co. | Tulsa, OK 74119 | Oil & Gas Operator | Oct 1998 |
| 700 | Service Drilling Co., L.L.C. | Tulsa, OK 74119 | Oil & Gas Operator | Oct 2003 |