| 501 | R & S Oil Company | Tonkawa, OK 74653 | Oil & Gas Operator | Nov 2013 |
| 502 | R & S Operating | Perry, OK 73077 | Oil & Gas Operator | Jan 2013 |
| 503 | R C Holdings LLC | Garber, OK 73738-5423 | Oil & Gas Operator | Oct 2025 |
| 504 | R C Taylor Operating Company LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | May 2026 |
| 505 | R E Blaik Inc | Edmond, OK 73013-6675 | Oil & Gas Operator | Apr 2026 |
| 506 | Ra-Jac LLC | Norman, OK 73069 | Oil & Gas Operator | May 2026 |
| 507 | Raf Oil Company | Oklahoma City, OK 73120-1944 | Oil & Gas Operator | Jul 2013 |
| 508 | Rahm Oil Company | Enid, OK 73703 | Oil & Gas Operator | Mar 2011 |
| 509 | Ram Asset Management Co | Oklahoma City, OK 73114 | Oil & Gas Operator | Mar 2015 |
| 510 | Ram Oil & Gas | Blackwell, OK 74631 | Oil & Gas Operator | May 2013 |
| 511 | Rama Operating Company Inc | Stafford, KS 67578 | Oil & Gas Operator | May 2026 |
| 512 | Ramco Oil & Gas Inc | Midland, TX 79701 | Oil & Gas Operator | Nov 2006 |
| 513 | Rampage Energy Inc | Bristow, OK 74010-6415 | Oil & Gas Operator | Apr 2020 |
| 514 | Ramsey Engineering Inc | Oklahoma City, OK 73118 | Oil & Gas Operator | Apr 1993 |
| 515 | Ramsey Property MGMT Inc | Oklahoma City, OK 73120-1955 | Oil & Gas Operator | Mar 2019 |
| 516 | Range Production Company | Fort Worth, TX 76102 | Oil & Gas Operator | Sep 2021 |
| 517 | Range Production Company, LLC | Fort Worth, TX 76102 | Oil & Gas Operator | Apr 2026 |
| 518 | Rays Energy Partners LLC | Dallas, TX 75230 | Oil & Gas Operator | Apr 2026 |
| 519 | Red Fork (USA) Investments Inc | Midland, TX 79710-0272 | Oil & Gas Operator | May 2019 |
| 520 | Red Fork Valley Oil & Gas Co | Cushing, OK 74023 | Oil Operator | Dec 2014 |
| 521 | Red Tail Properties, LLC | Tulsa, OK 74107-3443 | Oil Operator | Apr 2026 |
| 522 | Reliance Trusts | Dallas, TX 75244 | Oil & Gas Operator | Nov 1995 |
| 523 | Renegade Operating Company | Aurora, CO 80016 | Oil & Gas Operator | Aug 2023 |
| 524 | Republic Resources Corporation | Oklahoma City, OK 73102-3081 | Oil & Gas Operator | May 2021 |
| 525 | Resources Operating Co Inc | Rogers, AR 72756 | Oil & Gas Operator | Oct 2025 |
| 526 | Revelation Resources | Cypress, TX 77410-2578 | Oil & Gas Operator | Apr 2026 |
| 527 | Revilo Exploration, Inc. | Richardson, TX 75081 | Oil & Gas Operator | Jul 2021 |
| 528 | Rhoades Oil Co | Tulsa, OK 74136-5575 | Oil & Gas Operator | Aug 2013 |
| 529 | Richard C Sullins Credit Shelter Trust | Perry, OK 73077 | Gas Operator | Feb 2025 |
| 530 | Ricks Exploration Co | Oklahoma City, OK 73112 | Oil & Gas Operator | Mar 2015 |
| 531 | Riviera Operating, LLC | Houston, TX 77002 | Oil & Gas Operator | May 2026 |
| 532 | RKK Production Company | Mustang, OK 73064 | Oil & Gas Operator | May 2026 |
| 533 | Roberson, Joe | Vernon, TX 76385 | Oil & Gas Operator | Feb 2015 |
| 534 | Rocking Chair Energy Partners LLC | Morris, OK 74445 | Oil & Gas Operator | Apr 2026 |
| 535 | Rodman Petroleum Corp. | Odessa, TX 79768 | Oil & Gas Operator | Jul 2023 |
| 536 | Ron & Dan'S Oil LTD | Barnsdall, OK 74002-0628 | Oil & Gas Operator | May 2011 |
| 537 | Roth Gary E | Tonkawa, OK 74653-2033 | Oil & Gas Operator | Jan 2020 |
| 538 | Royal Oil & Gas Corp. | Indiana, PA 15701 | Oil & Gas Operator | Apr 2014 |
| 539 | Royalty Petroleum Company | Oklahoma City, OK 73120 | Gas Operator | Feb 2002 |
| 540 | RR Oil Well Operations LLC | Ringwood, OK 73768 | Oil & Gas Operator | May 2026 |
| 541 | Russell Oil Company | Haskell, OK 74436 | Oil & Gas Operator | Apr 2014 |
| 542 | S & J Oil Company | Ellinwood, KS 67526 | Oil Operator | Jun 2000 |
| 543 | S M Brothers Investments LLC | Denver, CO 80210-6059 | Oil Operator | Mar 2026 |
| 544 | S T Industries Inc | Drumright, OK 74030 | Oil & Gas Operator | Mar 2011 |
| 545 | Sage NR Ok LLC | Tulsa, OK 74136 | Oil & Gas Operator | May 2026 |
| 546 | Samedan Oil Corporation | Houston, TX 77067 | Oil & Gas Operator | Dec 2019 |
| 547 | Samhill LLC | Tonkawa, OK 74653-5533 | Oil & Gas Operator | Apr 2026 |
| 548 | Samson Resources Company | Tulsa, OK 74103 | Oil & Gas Operator | Apr 2026 |
| 549 | Sand Point Production Inc | Oklahoma City, OK 73172 | Oil & Gas Operator | Apr 2026 |
| 550 | Sandridge Energy, Inc. | Oklahoma City, OK 73102 | Oil & Gas Operator | May 2018 |
| 551 | Sandridge Exploration And Production LLC | Oklahoma City, OK 73104 | Oil & Gas Operator | Jul 2026 |
| 552 | Sandstone Resources, Inc. | Houston, TX 77043 | Oil & Gas Operator | Jul 2026 |
| 553 | Santa Fe Energy Company | Midland, TX 79701 | Oil & Gas Operator | Dec 2015 |
| 554 | Santa Fe Energy Operating Partner LP | Midland, TX 79701 | Oil & Gas Operator | Sep 2004 |
| 555 | Schonwald Supply Company | Oklahoma City, OK 73101-1571 | Oil & Gas Operator | May 1999 |
| 556 | Scissortail Energy LLC | Tulsa, OK 74137-3644 | Oil & Gas Operator | May 2026 |
| 557 | Scout Energy Corporation | Edmond, OK 73083-1348 | Oil & Gas Operator | Apr 2026 |
| 558 | Seaboard Gas Company | Edmond, OK 73034 | Oil & Gas Operator | Feb 1999 |
| 559 | Seagull Energy E & P Inc | Houston, TX 77002 | Oil & Gas Operator | Jan 2015 |
| 560 | Seaport Inc | Oklahoma City, OK 73131 | Oil & Gas Operator | Apr 2026 |
| 561 | Selco Oil And Gas Inc | Alamo, CA 94507 | Oil & Gas Operator | May 2026 |
| 562 | Sensor Oil & Gas, Inc. | Duncan, OK 73534 | Oil & Gas Operator | May 2013 |
| 563 | Sentinel Petroleum Inc | Oklahoma City, OK 73102 | Oil & Gas Operator | Feb 2020 |
| 564 | Sequoyah Energy Holdings LLC | Oklahoma City, OK 73118 | Oil & Gas Operator | May 2026 |
| 565 | Service Drilling Co. | Tulsa, OK 74119 | Oil & Gas Operator | Oct 1998 |
| 566 | Service Drilling Co., L.L.C. | Tulsa, OK 74119 | Oil & Gas Operator | Oct 2003 |
| 567 | Settlers Energy Corporation | Oklahoma City, OK 73113 | Oil & Gas Operator | Apr 1998 |
| 568 | Shawver & Son Inc | Oklahoma City, OK 73154-0778 | Oil & Gas Operator | Dec 2025 |
| 569 | Shawver Energy Inc | Oklahoma City, OK 73154-0683 | Oil & Gas Operator | Apr 2014 |
| 570 | Shebester Inc | Maysville, OK 73057 | Oil & Gas Operator | Nov 1998 |
| 571 | Sheets George M & Judith A | Tonkawa, OK 74653 | Oil & Gas Operator | Apr 2026 |
| 572 | Shell Western Expl & Prod Inc | Houston, TX 77251 | Oil & Gas Operator | Mar 2015 |
| 573 | Short Oil Co. | Luling, TX 78648 | Oil & Gas Operator | Apr 2026 |
| 574 | Silver Pines Energy Corp. | Houston, TX 77005 | Oil & Gas Operator | Apr 2026 |
| 575 | Singer-Fleischaker Oil Op Co | Oklahoma City, OK 73102 | Oil & Gas Operator | Apr 2002 |
| 576 | Smith C W & Associates Inc | Oklahoma City, OK 73178-0105 | Oil & Gas Operator | Aug 2013 |
| 577 | Smith Petroleum Company | Spring, TX 77389 | Oil & Gas Operator | Jul 2026 |
| 578 | Sneed William A Bill | Cleveland, OK 74020-1007 | Oil & Gas Operator | Apr 2026 |
| 579 | SNR Operating, LLC | Nichols Hill, OK 73116 | Oil & Gas Operator | Jul 2026 |
| 580 | Snyder Oil Company | Fort Worth, TX 76102 | Oil & Gas Operator | Mar 2015 |
| 581 | Sooner Exploration & Development Co Inc | Enid, OK 73702-3525 | Oil & Gas Operator | Oct 2023 |
| 582 | Sopac Exploration Inc | Drumright, OK 74030 | Oil & Gas Operator | Jun 1993 |
| 583 | Sorrels J R Dba Cheyenne Oil Properties | Ponca City, OK 74601 | Oil & Gas Operator | Jul 2022 |
| 584 | Southwest Energy Development Inc | Bison, OK 73720 | Oil & Gas Operator | Apr 2026 |
| 585 | Southwest Petroleum Oil & Gas Explor LLC | San Bernardino, CA 92404-1010 | Oil & Gas Operator | Jun 2022 |
| 586 | Southwest Royalties, Inc. | Midland, TX 79710 | Oil & Gas Operator | Jul 2026 |
| 587 | Southwestern Exploration Consultants Inc | Oklahoma City, OK 73118-1116 | Oil & Gas Operator | May 2026 |
| 588 | Spark'S Energy Inc | Perry, OK 73077 | Oil & Gas Operator | Nov 2014 |
| 589 | Special Energy Corp. | Stillwater, OK 74076 | Oil & Gas Operator | Jul 2026 |
| 590 | Spess Oil Company Inc | Cleveland, OK 74020-4617 | Oil & Gas Operator | May 2026 |
| 591 | Spring Valley Oil & Gas Inc | Drummond, OK 73735 | Oil & Gas Operator | May 2026 |
| 592 | Stacy Operating LLC | Cushing, OK 74023 | Oil & Gas Operator | Apr 2026 |
| 593 | Statex Petroleum Inc | Dallas, TX 75229 | Oil & Gas Operator | Dec 2000 |
| 594 | Stevens & Tull, Inc. | Midland, TX 79702 | Oil & Gas Operator | Jun 2000 |
| 595 | Stewart K Petroleum Corp | Edmond, OK 73013 | Oil & Gas Operator | Mar 2015 |
| 596 | Still A B Wel-Service Inc | Drumright, OK 74030-0787 | Oil & Gas Operator | Jul 2019 |
| 597 | Still Alex B Estate Of | Sagle, ID 83860-0644 | Oil & Gas Operator | Nov 2018 |
| 598 | Stillwater Oil & Gas | Irving, TX 75062 | Oil & Gas Operator | Mar 2015 |
| 599 | Storm Exploration Inc | Skiatook, OK 74070-1014 | Oil & Gas Operator | Jan 2013 |
| 600 | Summit Resources Management LLC | Edmond, OK 73083 | Oil & Gas Operator | Apr 2026 |