| 401 | Petro-Lewis Corp. | | Oil & Gas Operator | Feb 1994 |
| 402 | Petroleum Develo | | Oil Operator | Sep 1986 |
| 403 | Petroleum Energy | | Oil & Gas Operator | Mar 1991 |
| 404 | Petroleum Enterp | | Oil & Gas Operator | Sep 1995 |
| 405 | Petroleum Incorp | | Oil & Gas Operator | Apr 1993 |
| 406 | Petroleum Property Services, Inc. | Wichita, KS 67202 | Oil & Gas Operator | Jun 2025 |
| 407 | Petroleum Techno | | Oil & Gas Operator | Dec 1996 |
| 408 | Petroleum Technologies, Inc. | Kansas City, MO 64112 | Oil & Gas Operator | Jun 2025 |
| 409 | Petropro Petroleum LLC | | Oil Operator | Jun 2025 |
| 410 | Petx Petroleum C | | Oil Operator | Nov 1993 |
| 411 | Phillips Oil Company, LLC | Wichita, KS 67211 | Oil Operator | Jun 2025 |
| 412 | Phillips Petrole | | Oil & Gas Operator | May 1995 |
| 413 | Phillips Petroleum Company | Houston, TX 77251 | Oil & Gas Operator | Mar 2013 |
| 414 | Phillips William | | Oil Operator | Jul 1989 |
| 415 | Pickrell Drilling Co., Inc. | Wichita, KS 67213 | Oil & Gas Operator | Jun 2025 |
| 416 | Pintail Petroleu | | Oil & Gas Operator | Dec 1995 |
| 417 | Pintail Petroleum, LTD. | Wichita, KS 67202 | Oil & Gas Operator | Apr 2021 |
| 418 | Pioneer Oil Company, Inc. | Vincennes, IN 47501 | Oil & Gas Operator | Jun 2025 |
| 419 | Pioneer Operatio | | Oil & Gas Operator | Mar 1986 |
| 420 | Pitman Creek, Inc. | Burlington, IA 52601 | Oil Operator | Dec 1992 |
| 421 | Plano Petroleum Corporation | McKinney, TX 75070 | Oil & Gas Operator | Jun 2025 |
| 422 | Plum Creek Energy, LLC | Ellinwood, KS 67526 | Oil & Gas Operator | Jun 2025 |
| 423 | Poor Boy Corporation | Ellinwood, KS 67526 | Oil Operator | Jun 2025 |
| 424 | Popp Operating, Inc. | Hoisington, KS 67544 | Oil Operator | Jun 2025 |
| 425 | Powers, Dixon D. | Great Bend, KS 67530 | Oil & Gas Operator | Oct 1995 |
| 426 | Prater Oil & Gas Operations, Inc. | Pratt, KS 67124 | Oil & Gas Operator | Jun 2025 |
| 427 | Premier Oil & Exploration Inc | Hutchinson, KS 67502 | Oil & Gas Operator | Jun 2025 |
| 428 | Production Drilling, Inc. | Hays, KS 67601 | Oil Operator | Jun 2025 |
| 429 | Prolific Resources LLC | Wichita, KS 67208 | Oil & Gas Operator | Jun 2025 |
| 430 | Prospect Oil & G | | Oil Operator | Feb 1996 |
| 431 | Prospect Oil & Gas Corp | Russell, KS 67665 | Oil Operator | Jun 2025 |
| 432 | Provine, B.R. | Wichita, KS 67226 | Oil Operator | Apr 2010 |
| 433 | Pyramid Corporat | | Oil & Gas Operator | Aug 1995 |
| 434 | Questar Exploration And Production Company Division Of Questar Urc Company | Oklahoma City, OK 73112 | Oil & Gas Operator | Feb 2023 |
| 435 | R J Operating Company | Albany, TX 76430 | Oil & Gas Operator | Jun 2025 |
| 436 | R. P. Nixon Operations, Inc | Hays, KS 67601 | Oil Operator | Jun 2025 |
| 437 | Ram Service - Mi | | Oil Operator | Sep 1994 |
| 438 | Rama Operating C | | Oil & Gas Operator | Dec 1996 |
| 439 | Rama Operating Co., Inc. | Stafford, KS 67578 | Oil & Gas Operator | Jun 2025 |
| 440 | Ramco Drilling S | | Oil & Gas Operator | Dec 1992 |
| 441 | Ramco Energy Corporation | FT. Lauderdale, FL 33312 | Oil & Gas Operator | Dec 2008 |
| 442 | Raney Oil Company | Lawrence, KS 66047 | Oil & Gas Operator | May 1999 |
| 443 | Range Oil Co., Inc. | Wichita, KS 67278 | Oil & Gas Operator | Jan 2020 |
| 444 | Range Oil Compan | | Oil & Gas Operator | Nov 1995 |
| 445 | Raymond Oil Co., Inc. | Wichita, KS 67201 | Oil & Gas Operator | Jun 2025 |
| 446 | Raymond Oil Comp | | Oil & Gas Operator | Dec 1996 |
| 447 | Reichlinger Business Services | | Oil Operator | Apr 2014 |
| 448 | Reif Oil & Gas Company LLC | Hoisington, KS 67544 | Oil Operator | Aug 2010 |
| 449 | Reif Oil Operati | | Oil Operator | Nov 1988 |
| 450 | Resource Operations, Inc. | Tulsa, OK 74157 | Oil & Gas Operator | May 2016 |
| 451 | Rice Engineering | | Oil & Gas Operator | Jul 1988 |
| 452 | Rice Production Company | | Oil Operator | Dec 2019 |
| 453 | Richlan Drilling | | Oil Operator | Dec 1994 |
| 454 | Richlan Drilling, A General Partnership | Beaver, KS 67525 | Oil & Gas Operator | Jun 2025 |
| 455 | Ritchie Explorat | | Oil & Gas Operator | Dec 1996 |
| 456 | Ritchie Exploration, Inc. | Wichita, KS 67278 | Oil & Gas Operator | Jun 2025 |
| 457 | Ritchie, A. Scott | Wichita, KS 67202 | Oil Operator | Mar 1988 |
| 458 | Riverside Petrol | | Oil Operator | Sep 1995 |
| 459 | RJM Company | Claflin, KS 67525 | Oil & Gas Operator | Jun 2025 |
| 460 | Robinowitz Oil C | | Oil Operator | Dec 1996 |
| 461 | Robinowitz Oil Company, A General Partnership | Tulsa, OK 74136 | Oil & Gas Operator | Feb 2023 |
| 462 | Robl-Six, Inc. | Ellinwood, KS 67526 | Oil Operator | Dec 2019 |
| 463 | Rodgers, Murray | Sedan, KS 67361 | Oil Operator | Oct 1996 |
| 464 | Rosel Energy, Inc. | Liberal, KS 67901 | Oil & Gas Operator | Jul 2004 |
| 465 | Roxana Corporati | | Oil & Gas Operator | Feb 1993 |
| 466 | Royal Drilling Inc | Russell, KS 67665 | Oil Operator | Jun 2025 |
| 467 | Rupe Oil Company, Inc. | Wichita, KS 67278 | Oil & Gas Operator | Jun 2025 |
| 468 | Russco Energy In | | Oil Operator | Jun 1994 |
| 469 | Russell Oil, Inc. | Edmond, OK 73083 | Oil Operator | Jun 2025 |
| 470 | Ryan, Daniel J. | Oklahoma City, OK 73139 | Oil Operator | Sep 2003 |
| 471 | S & K Oil Compan | | Oil Operator | Sep 1989 |
| 472 | S & S Oil Leasing | Chase, KS 67524 | Oil Operator | Jun 2025 |
| 473 | S & S Oil, L.L.C. | Chase, KS 67524 | Oil Operator | Jun 2025 |
| 474 | Sage Drilling Co | Wichita, KS 67202 | Oil & Gas Operator | Nov 1998 |
| 475 | Samson Properties, Incorporated | Tulsa, OK 74103 | Oil & Gas Operator | Feb 2008 |
| 476 | Samson Resources | | Oil Operator | Jan 1994 |
| 477 | Samuel Gary Jr. & Associates, Inc. | Denver, CO 80202 | Oil & Gas Operator | Jun 2025 |
| 478 | Scavenger Oil Co., Inc. | Englewood, CO 80111 | Oil & Gas Operator | Mar 2000 |
| 479 | Scheck Oil Operation | | Oil & Gas Operator | Jun 2025 |
| 480 | Schlobohm Starr | | Oil Operator | Dec 1996 |
| 481 | Schreiber Oil Co. | | Oil Operator | Dec 2009 |
| 482 | Semgas Gathering LLC | Tulsa, OK 74136 | Gas Operator | Jul 2009 |
| 483 | Shaida, John H. | Wichita, KS 67226 | Oil & Gas Operator | Oct 2025 |
| 484 | Sharp Engineerin | | Oil Operator | Aug 1995 |
| 485 | Shaw Robert Lesl | | Oil Operator | Oct 1989 |
| 486 | Shelby Resources LLC | Denver, CO 80207 | Oil & Gas Operator | Jun 2025 |
| 487 | Shelley, Randall D. | Wichita, KS 67202 | Oil Operator | Jun 2025 |
| 488 | Sher-Lon Corpora | | Oil Operator | Apr 1994 |
| 489 | Shields Oil Prod | | Oil & Gas Operator | Aug 1995 |
| 490 | Shields Oil Producers Inc. | Russell, KS 67665 | Oil Operator | Jun 2025 |
| 491 | Siemsen Operating, LLC | Holyrood, KS 67450 | Oil Operator | Jun 2025 |
| 492 | Sierra Petroleum | | Oil & Gas Operator | Sep 1986 |
| 493 | Smith Oil Operations | | Oil & Gas Operator | Jun 2025 |
| 494 | Smith Richard F | | Oil Operator | Jun 1995 |
| 495 | Smoky Valley Res | | Oil & Gas Operator | Dec 1995 |
| 496 | Southern States | | Oil & Gas Operator | Jul 1988 |
| 497 | Southwind Petroleum Corp. | Wichita, KS 67203 | Oil & Gas Operator | Jun 2022 |
| 498 | Stepco Incorpora | | Oil Operator | Nov 1994 |
| 499 | Stepco Oil, Inc. | Ellinwood, KS 67526 | Oil Operator | Jan 2020 |
| 500 | Stepco, Inc. | Ellinwood, KS 67526 | Oil Operator | Feb 2005 |