| 601 | Robson Petroleum Company | Tulsa, OK 74104 | Oil & Gas Operator | Jan 1995 |
| 602 | Roka Management Inc | Oklahoma City, OK 73139 | Oil & Gas Operator | Feb 2026 |
| 603 | Roka Resources Inc | Oklahoma City, OK 73139 | Oil & Gas Operator | Feb 2026 |
| 604 | Rosetta Resources Operating LP | San Antonio, TX 78216 | Oil & Gas Operator | Jun 2026 |
| 605 | Rover Operating, LLC | Chicago, IL 60606 | Oil & Gas Operator | Jan 2026 |
| 606 | Rox Exploration Inc | Norman, OK 73069-6301 | Oil & Gas Operator | Mar 2026 |
| 607 | Rupe Oil Company Inc | Wichita, KS 67278 | Oil & Gas Operator | Feb 2026 |
| 608 | Russell D Meloy Oil & Gas Co | Enid, OK 73703-1623 | Oil & Gas Operator | Feb 2026 |
| 609 | Rustler Energy LLC | Lindsay, OK 73052 | Oil & Gas Operator | Feb 2026 |
| 610 | Ryan Petroleum Corp | Oklahoma City, OK 73102-9024 | Oil & Gas Operator | Aug 1994 |
| 611 | S & H Tank Service Of Okla | Lindsay, OK 73052 | Oil & Gas Operator | Mar 2017 |
| 612 | S & S Oil Company | Electra, TX 76360 | Oil & Gas Operator | Jun 2026 |
| 613 | S & S Star Operating, LLC | Oklahoma City, OK 73101 | Oil & Gas Operator | Mar 2026 |
| 614 | S & T SWD LLC | Clinton, OK 73601-3130 | Oil Operator | Feb 2017 |
| 615 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 616 | Samson Hydrocarbons Company | Tulsa, OK 74103 | Oil & Gas Operator | Nov 2016 |
| 617 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2026 |
| 618 | Sand Point Production Inc | Oklahoma City, OK 73172 | Oil & Gas Operator | Feb 2026 |
| 619 | Sanguine Gas Exploration, LLC | Tulsa, OK 74119 | Oil & Gas Operator | Jun 2026 |
| 620 | Sanook Inc | Oklahoma City, OK 73156-0548 | Oil & Gas Operator | Jan 2007 |
| 621 | Santa Fe Energy Company | Midland, TX 79701 | Oil & Gas Operator | Dec 2015 |
| 622 | Santa Fe Energy Operating Partner LP | Midland, TX 79701 | Oil & Gas Operator | Sep 2004 |
| 623 | Santa Fe Minerals, Inc. | Dallas, TX 75240 | Oil & Gas Operator | Sep 2013 |
| 624 | Santa Rita Resources Inc & Subs | | Oil & Gas Operator | Mar 2015 |
| 625 | Scout Energy Management LLC | Dallas, TX 75240 | Oil & Gas Operator | Jun 2026 |
| 626 | Seagull Energy E & P Inc | Houston, TX 77002 | Oil & Gas Operator | Jan 2015 |
| 627 | Seagull Mid-South Inc | Houston, TX 77002 | Oil & Gas Operator | Mar 2015 |
| 628 | Seaport Inc | Oklahoma City, OK 73131 | Oil & Gas Operator | Feb 2026 |
| 629 | Sensor Oil & Gas, Inc. | Duncan, OK 73534 | Oil & Gas Operator | May 2013 |
| 630 | Sharber Billy Jack Operating | Konawa, OK 74849-0071 | Oil & Gas Operator | Mar 2015 |
| 631 | Shaw Thomas P | Tulsa, OK 74105-7327 | Oil & Gas Operator | Mar 2015 |
| 632 | Shell Oil Company | Houston, TX 77210 | Oil & Gas Operator | Apr 2015 |
| 633 | Sheridan Production Company, LLC | Houston, TX 77056 | Oil & Gas Operator | Feb 2026 |
| 634 | Shoreline Operating LLC | Oklahoma City, OK 73113 | Oil & Gas Operator | Mar 2026 |
| 635 | Shoshone Oil And Gas Inc | Lindsay, OK 73052-0217 | Oil & Gas Operator | Jan 2020 |
| 636 | Singer Oil Co LLC | Hennessey, OK 73742 | Oil & Gas Operator | Mar 2026 |
| 637 | Singer-Fleischaker Oil Op Co | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2002 |
| 638 | Skycap Energy, LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | Jun 2026 |
| 639 | SM Energy Company | Midland, TX 79707 | Oil & Gas Operator | Jun 2026 |
| 640 | Smiley Drilling Co | Oklahoma City, OK 73156-0773 | Oil & Gas Operator | Apr 1999 |
| 641 | Smith Production Co. | Wichita Falls, TX 76308 | Oil & Gas Operator | Jun 2026 |
| 642 | Snelgrooes Oil Company Inc | Maysville, OK 73057-0631 | Oil & Gas Operator | Nov 2014 |
| 643 | SNR Operating, LLC | Nichols Hill, OK 73116 | Oil & Gas Operator | Jun 2026 |
| 644 | Snyder Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2015 |
| 645 | Sonata Oil & Gas Corp Inc | Stratford, OK 74812 | Oil & Gas Operator | Apr 2014 |
| 646 | Sorrels J R Dba Cheyenne Oil Properties | Ponca City, OK 74601 | Oil & Gas Operator | Jul 2022 |
| 647 | Southcreek Petroleum Co LLC | Blanchard, OK 73010-4911 | Oil & Gas Operator | Feb 2026 |
| 648 | Southern Resources Inc | Oklahoma City, OK 73120 | Oil & Gas Operator | Mar 2026 |
| 649 | Southfourk Partners LLC | Blanchard, OK 73010-7209 | Oil Operator | Feb 2026 |
| 650 | Southwestern Oil Corporation | Oklahoma City, OK 73106 | Oil & Gas Operator | Mar 2026 |
| 651 | SP Energy Development Company | Seattle, WA 98101-3277 | Oil & Gas Operator | Mar 2015 |
| 652 | Sparks Mick Oil Company Inc | Jennings, OK 74038-0250 | Oil & Gas Operator | Mar 2026 |
| 653 | Sparks Petroleum Company | Oklahoma City, OK 73128 | Oil & Gas Operator | Mar 1998 |
| 654 | Sparks Resources Inc | Bristow, OK 74010 | Oil & Gas Operator | Mar 2026 |
| 655 | Spartan Resources LLC | Oklahoma City, OK 73116 | Oil & Gas Operator | Mar 2026 |
| 656 | Speller Oil Corporation | Oklahoma City, OK 73112 | Oil & Gas Operator | Feb 2026 |
| 657 | Spess Oil Company Inc | Cleveland, OK 74020-4617 | Oil & Gas Operator | Mar 2026 |
| 658 | Spring Operating Company | Edmond, OK 73034 | Oil & Gas Operator | Mar 2026 |
| 659 | St. Mary Operating Company | Denver, CO 80203 | Oil & Gas Operator | Mar 2019 |
| 660 | Staab Alan R | Tulsa, OK 74114-4213 | Oil & Gas Operator | Sep 2010 |
| 661 | Staghorn Energy, LLC | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2026 |
| 662 | Stanolind Operating LLC | Midland, TX 79702 | Oil & Gas Operator | Apr 2021 |
| 663 | Stauros Operating Company | Edmond, OK 73083-2707 | Oil & Gas Operator | Mar 2001 |
| 664 | Stephens & Johnson Operating Co. | Wichita Falls, TX 76307 | Oil & Gas Operator | Jun 2026 |
| 665 | Stephens Exploration, Inc. | Dallas, TX 75367 | Oil & Gas Operator | Mar 2026 |
| 666 | Stephens Production Company | The Woodlands, TX 77381 | Oil & Gas Operator | Mar 2026 |
| 667 | Stewart Inc | Ringling, OK 73456 | Oil & Gas Operator | Mar 2026 |
| 668 | Stoneriver Energy, LLC | Lubbock, TX 79424 | Oil & Gas Operator | Jun 2026 |
| 669 | Strat Land Exploration Company | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2026 |
| 670 | Streamline Oil And Gas Inc | Lindsay, OK 73052 | Oil & Gas Operator | Mar 2026 |
| 671 | Sullivan And Company LLC | Tulsa, OK 74119 | Oil & Gas Operator | Feb 2026 |
| 672 | Sundown Energy, Inc. | Dallas, TX 75240 | Oil & Gas Operator | May 2025 |
| 673 | Superior Oil Co. | Denver, CO 80217-5444 | Oil & Gas Operator | Feb 2001 |
| 674 | Swift Energy Company | Houston, TX 77060 | Oil & Gas Operator | Mar 2021 |
| 675 | Switchgrass E&P Operating, LLC | The Woodlands, TX 77380 | Oil & Gas Operator | Feb 2026 |
| 676 | SWN Production LLC | Spring, TX 77389-4954 | Oil & Gas Operator | Feb 2022 |
| 677 | T Investments Inc | Oklahoma City, OK 73118-1401 | Oil & Gas Operator | Mar 2011 |
| 678 | T2 Operating Corporation | Denver, CO 80202 | Oil & Gas Operator | Apr 2026 |
| 679 | Tapoil Inc | Elmore City, OK 73433-9077 | Oil & Gas Operator | Jul 2021 |
| 680 | Tat, Inc. | Oklahoma City, OK 73127 | Oil & Gas Operator | Feb 2023 |
| 681 | Taurus Operating, Inc. | Midland, TX 79710 | Oil & Gas Operator | Jun 2026 |
| 682 | Tbi Exploration Inc | Englewood, CO 801556525 | Oil & Gas Operator | Jun 2011 |
| 683 | Te-Ray Energy Inc | Oklahoma City, OK 73108 | Oil & Gas Operator | Feb 2026 |
| 684 | Te-Ray Resources, LLC | Oklahoma City, OK 73142 | Oil & Gas Operator | Jun 2026 |
| 685 | Technical Energy Services, Inc. | Norman, OK 73070 | Oil & Gas Operator | Feb 2026 |
| 686 | Tenneco Oil Company | Oklahoma City, OK 73125 | Oil & Gas Operator | Dec 2025 |
| 687 | Territory Resources LLC | Stillwater, OK 74074-1869 | Oil & Gas Operator | Mar 2026 |
| 688 | Tessera Energy LLC | Oklahoma City, OK 73120 | Oil & Gas Operator | Feb 2026 |
| 689 | Texaco Exploration & Prod Inc | Houston, TX 77236 | Oil & Gas Operator | Feb 2026 |
| 690 | Texaco Inc | Kingfisher, OK 73750 | Oil & Gas Operator | Dec 2017 |
| 691 | Texas Crude Exploration Inc | Fort Worth, TX 76116 | Oil & Gas Operator | Aug 1992 |
| 692 | Texas Energy & Environmental | Houston, TX 77070 | Oil & Gas Operator | Nov 1998 |
| 693 | The Quintin Little Company Inc | Ardmore, OK 73401 | Oil & Gas Operator | Mar 2026 |
| 694 | Thomas J L Engineering Inc | Edmond, OK 73003-0026 | Oil & Gas Operator | Jul 2016 |
| 695 | Thomas, R. W. Inc. | Norman, OK 73070 | Oil & Gas Operator | Apr 2015 |
| 696 | Thunder Oil & Gas, LLC | Ardmore, OK 73402 | Oil & Gas Operator | Mar 2026 |
| 697 | Tide West Oil Company | Tulsa, OK 74136 | Oil & Gas Operator | Mar 2021 |
| 698 | Tidemark Exploration | Tulsa, OK 74170 | Oil & Gas Operator | May 2005 |
| 699 | Titan Resources LTD | Limaville, OH 44640 | Oil & Gas Operator | Mar 2026 |
| 700 | TNT Operating Company Inc | Blanchard, OK 73010 | Oil & Gas Operator | Feb 2026 |