| Monsalve Petroleum Co | 101462 | — | 1 | 1 |
| Monsanto | 101463 | Englewood | 17 | 2 |
| Monte Grande Explor Inc | 101464 | — | 0 | 0 |
| Montezuma Well Services Inc | 101465 | Montezuma Creek | 0 | 0 |
| Montgomery & Jeffries | 101466 | — | 1 | 1 |
| Monticello Oil Company | 101467 | — | 1 | 1 |
| Monumental Oil Co | 101468 | — | 5 | 1 |
| Moore, H D | 101469 | — | 1 | 1 |
| Moore, J Hiram | 101470 | Midland | 2 | 1 |
| Moore, John W | 101471 | — | 4 | 1 |
| Moose Mountain Divide #1, LLCActive | 101472 | Roosevelt | 1 | 1 |
| Morning Gun Exploration, LLC | 104857 | Denver | 0 | 0 |
| Morningstar Partners LP | 101473 | Ft Worth | 0 | 0 |
| Mosbacher Production Co | 101474 | Casper | 2 | 1 |
| Mosbacher, Robert | 101475 | Houston | 3 | 1 |
| Mount Peale Corporation | 101476 | Salt Lake City | 1 | 1 |
| Mountain Energy & Resources Inc | 101478 | Palisade | 0 | 0 |
| Mountain Fuel Supply Co | 101479 | Salt Lake City | 60 | 16 |
| Mountain Oil And Gas IncActive | 101480 | Roosevelt | 1 | 1 |
| Mountain Oil Inc | 101481 | Provo | 0 | 0 |
| Mountain Oil Inc | 101482 | Provo | 0 | 0 |
| Mountain Petroleum Corp | 101483 | Denver | 2 | 1 |
| Mountain Resource Corp | 101484 | Salt Lake City | 13 | 1 |
| Mountain Sage Minerals, LLCActive | 105437 | Irvine | 1 | 1 |
| Mountain States Petroleum Corp | 101485 | Farmington | 0 | 0 |
| Mountain States Res Inc | 101486 | Cut Bank | 4 | 1 |
| Mountain West Oil Company | 101487 | — | 2 | 1 |
| MountainWest Pipeline, LLCActive | 105278 | Salt Lake City | 64 | 2 |
| MPLX | 105464 | Vernal | 0 | 0 |
| Msc Exploration LP | 101488 | Houston | 6 | 1 |
| Mt States Development | 101489 | — | 1 | 1 |
| Mt States Drilling Co | 101490 | Denver | 1 | 1 |
| Mt States Exploration Co | 101491 | — | 1 | 1 |
| Mt Vernon Oil Co | 101492 | — | 1 | 1 |
| Mulvey, G H | 101493 | — | 1 | 1 |
| Munson, F S | 101494 | — | 0 | 0 |
| Murdoch Oil Co Inc | 101495 | Bluff | 1 | 1 |
| Murer, C F & G J Kirn | 101496 | Denver | 2 | 1 |
| Murphy Construction | 101497 | — | 1 | 1 |
| Murphy Corp | 101498 | — | 1 | 1 |
| Mustang Fuel Corporation | 101500 | Vernal | 0 | 0 |
| Mustang Fuel Corporation | 101501 | Oklahoma City | 21 | 1 |
| Mustang Fuel Marketing Company | 101502 | Oklahoma City | 0 | 0 |
| Mutual Oil Co | 101503 | — | 2 | 1 |
| Mutual Oil of America | 101504 | Reno | 1 | 1 |
| Myco Industries Inc | 101505 | Artesia | 1 | 1 |
| Nacogdoches Oil & Gas Inc | 101506 | Hobbs | 6 | 1 |
| NADK, LLCActive | 104351 | Orem | 2 | 1 |
| NAE LLC | 101507 | Denver | 19 | 1 |
| NAH Utah, LLCActive | 104707 | Salt Lake City | 4 | 1 |
| Nak, John A | 101508 | — | 1 | 1 |
| National Oil & Gas Co | 101512 | — | 1 | 1 |
| National Oil Company | 101513 | Denver | 1 | 1 |
| National Security Corp | 101514 | — | 0 | 0 |
| National Treasure Mines Co | 101516 | Salt Lake City | 3 | 2 |
| Natomas North America Inc | 101517 | Denver | 4 | 1 |
| Natural Gas Corp of CA | 101518 | Vernal | 58 | 5 |
| Natural Gas Corp of Utah | 101519 | N Salt Lake City | 0 | 0 |
| Navajo Nation Oil & Gas Co | 101520 | Window Rock | 1 | 1 |
| Navajo Oil Co | 101521 | — | 1 | 1 |
| Navajo Petroleum Corp | 101522 | — | 1 | 1 |
| Navajo Refining Co | 101523 | Artesia | 0 | 0 |
| Navajo Tribe | 101524 | — | 1 | 1 |
| Navanick Disposal Pits | 101525 | — | 0 | 0 |
| Nbb Oil & Gas Partners USA | 101526 | Denver | 0 | 0 |
| Ned B Mitchell, Inc | 101528 | Altamont | 0 | 0 |
| Needle Exploration Company | 101529 | Ely | 1 | 1 |
| Negaunee, LLCActive | 101530 | Pewaukee | 2 | 1 |
| Nephi City | 101531 | Nephi | 0 | 0 |
| Neptune Exploration LTD | 101532 | — | 1 | 1 |
| Neuta Energy Corporation | 101533 | New Orleans | 0 | 0 |
| Nevills, W E | 101534 | — | 2 | 1 |
| New Jersey Natural Res Co | 101535 | Vernal | 0 | 0 |
| New Water Financial LLCActive | 101536 | Windsor | 2 | 1 |
| Newburg & Ingram | 101537 | — | 2 | 1 |
| Newfield Production Company | 101538 | The Woodlands | 0 | 0 |
| Newfield Rocky Mountains, Inc. | 104438 | — | 0 | 0 |
| Newman, Larry A | 101541 | — | 2 | 1 |
| Newman, R E Et Al | 101542 | — | 1 | 1 |
| Ngc Energy Company | 101543 | Vernal | 0 | 0 |
| Ngc Oil Trading & Trans | 101544 | Houston | 0 | 0 |
| NGL Supply Terminal Solution Mining, LLCActive | 101545 | Salt Lake City | 5 | 1 |
| Nicks Disposal LLC | 101546 | Altamont | 0 | 0 |
| Nicor Exploration Co | 101547 | Golden | 1 | 1 |
| Nitronics Corporation | 101548 | — | 1 | 1 |
| NNOGC Exploration & Production, LLCActive | 101549 | Window Rock | 63 | 1 |
| Noble Energy Inc | 101550 | Houston | 1 | 1 |
| Norcen Explorer Inc | 101551 | Houston | 0 | 0 |
| Norris Oil Company | 101552 | — | 1 | 1 |
| North American Resour Co | 101553 | Butte | 2 | 1 |
| North American Royalties | 101554 | Chattanooga | 0 | 0 |
| North Central Oil Corp | 101555 | — | 0 | 0 |
| North Plains Corp | 101556 | Littleton | 0 | 0 |
| North Plains Corp | 101557 | Roosevelt | 0 | 0 |
| North Shore Exploration & Production, LLCActive | 104569 | Broomfield | 56 | 1 |
| North, Charles R | 101560 | — | 1 | 1 |
| Northern Oil Co | 101561 | — | 1 | 1 |
| Northland Resources | 101562 | Rangely | 5 | 1 |
| Northridge Energy Mkg Corp | 101563 | Houston | 0 | 0 |
| Northstar Gas Company of TexasActive | 101564 | Houston | 3 | 1 |
| Northstar Gas, Inc.Active | 101565 | Orem | 8 | 2 |
| Northwest Crude Corp | 101566 | Englewood | 0 | 0 |
| Northwest Exploration Co | 101567 | Salt Lake City | 1 | 1 |
| Northwest Pipeline | 101568 | — | 2 | 1 |
| Northwest Production | 101569 | — | 1 | 1 |
| Norwood Oil Company | 101571 | Farmington | 1 | 1 |
| Nova Natural Res Corp | 101572 | Denver | 1 | 1 |
| Nova Petroleum Corp | 101573 | Salt Lake City | 1 | 1 |
| NP Energy Corporation | 101574 | Englewood | 32 | 1 |
| Nutech Drilling | 101575 | Casper | 1 | 1 |
| Oak Oil & Gas Company Inc | 101576 | Salt Lake City | 3 | 1 |
| Oberom Oil Company | 101577 | — | 1 | 1 |
| Obrien Goins & Simpson Ex | 101578 | Midland | 0 | 0 |
| Occidental Petroleum Co | 101579 | Denver | 3 | 1 |
| Ocean Energy Inc | 101580 | Newcastle | 0 | 0 |
| Odegard Resources/Omni Exp | 101581 | Columbus | 4 | 1 |
| Odessa Naturel Corp | 101582 | — | 9 | 4 |
| Ogle Corp & Hawthorn Oil | 101583 | — | 1 | 1 |
| Ohio Oil Company | 101584 | — | 2 | 2 |
| Oil and Gas Acquisitions Inc | 101585 | Parker | 0 | 0 |
| Oil Co of San Juan | 101586 | — | 2 | 1 |
| Oil Development Co | 101587 | — | 9 | 3 |
| Oil Energy Inc | 101588 | — | 0 | 0 |
| Oil Inc | 101589 | — | 10 | 2 |
| Oil Resources Incorporated | 101590 | — | 0 | 0 |
| Oil Securities & Gas Corp | 101591 | — | 5 | 2 |
| Oilman Inc | 101592 | — | 1 | 1 |
| Old Emery Oil Co | 101593 | — | 1 | 1 |
| Olympic Exploration Inc | 101594 | Denver | 0 | 0 |
| Omimex Petroleum Inc | 101595 | Fort Worth | 0 | 0 |
| Onshore Royalties LLC | 101596 | Victoria | 2 | 1 |
| Ops Group Limited | 101597 | Houston | 0 | 0 |
| Orbis Ex-Im Utah Inc | 101598 | Salt Lake City | 0 | 0 |
| Orion-Smith Oil Properties | 101599 | Amarillo | 0 | 0 |
| Oryx Energy Company | 101601 | Oklahoma City | 0 | 0 |
| Oso Oil & Gas Properties LLC | 101602 | Price | 2 | 1 |
| Otis Energy Inc | 101603 | Denver | 0 | 0 |
| Overthrust Oil Royalty Crp | 101604 | Littleton | 0 | 0 |
| Overthrust Oil Royalty Crp | 101605 | Salt Lake City | 0 | 0 |
| Ovintiv Production, Inc. | 104921 | The Woodlands | 0 | 0 |
| Ovintiv USA, Inc.Active | 105162 | The Woodlands | 1,139 | 3 |
| Owen, H | 101606 | — | 1 | 1 |
| Owen, K D | 101607 | — | 1 | 1 |
| Owl SWD Operating, LLC | 101608 | Dallas | 0 | 0 |
| Oxbow Properties Inc | 101609 | Centennial | 0 | 0 |
| Oxoco | 101610 | Houston | 0 | 0 |
| Oxy Petroleum Inc | 101611 | — | 0 | 0 |
| Oxy USA Inc | 101612 | Houston | 4 | 3 |
| P&M Petroleum Management | 101613 | Denver | 7 | 1 |
| P-2 Oil | 101614 | Vernal | 1 | 1 |
| Pacer Energy Marketing LLC | 101615 | Tulsa | 0 | 0 |
| Pacific Coast Gas Corp | 101616 | — | 2 | 1 |
| Pacific Energy & Mining Company | 101617 | Reno | 5 | 1 |
| Pacific Natural Gas Explor | 101619 | — | 24 | 6 |
| Pacific San Juan | 101620 | — | 1 | 1 |
| Pacific States | 101621 | — | 1 | 1 |
| Pacific Trans Supply | 101622 | Vernal | 16 | 5 |
| Pacific Western Oil Corp | 101623 | — | 4 | 3 |
| Pack, S D | 101624 | — | 1 | 1 |
| Page Petroleum Inc | 101626 | Calgary, Alberta | 3 | 2 |
| Page Petroleum Inc | 101627 | Calgary, Alberta | 0 | 0 |
| Paiute Oil & Mining Corp | 101628 | Salt Lake City | 4 | 2 |
| Paiute Oil & Mining Corp | 101629 | Vernal | 0 | 0 |
| Palmer Oil & Gas Co | 101630 | Billings | 0 | 0 |
| Palo Pinto Oil Co | 101631 | — | 3 | 1 |
| Pan American Energy, LLC | 105363 | Salt Lake City | 0 | 0 |
| Pan American Petroleum Cor | 101632 | — | 68 | 14 |
| Pancanadian Petroleum Company | 101633 | Houston | 0 | 0 |
| Pancanadian Petroleum Company | 101634 | Calgary, Alberta | 1 | 1 |
| Pannonian Energy Inc | 101635 | Englewood | 8 | 1 |
| Paradise Energy LLC | 101636 | Spanish Fork | 0 | 0 |
| Paradox Midstream LLC (Subsidiary) | 101637 | Houston | 0 | 0 |
| Paradox Midstream, LLC | 104783 | Houston | 0 | 0 |
| Paradox Production Corp | 101638 | — | 5 | 1 |
| Paradox Upstream, LLC | 101639 | Houston | 21 | 1 |
| Parallel Petroleum Corp | 101640 | Midland | 1 | 1 |
| Parallel Petroleum LLC | 101641 | Midland | 6 | 1 |
| Parker & Parsley Prod LP | 101642 | Oklahoma City | 0 | 0 |
| Parker Energy Tech Inc | 101643 | Salt Lake City | 4 | 1 |
| Parry Oil Co | 101644 | — | 1 | 1 |
| Parsons, R E | 101645 | — | 2 | 1 |
| Patara Oil & Gas, LLC | 101646 | La Sal | 8 | 1 |
| Patara Oil & Gas, LLC | 101647 | La Sal | 0 | 0 |
| Patina Oil & Gas Corp | 101648 | Denver | 0 | 0 |
| Patmos Energy LLC | 101649 | Spanish Fort | 0 | 0 |
| Patmos Energy LLC | 101650 | Spanish Fort | 3 | 1 |
| Patrick Petroleum | 101651 | Denver | 6 | 1 |
| Paul T Walton & Assoc | 101652 | Salt Lake City | 1 | 1 |
| Pauley, Edwin W | 101653 | Los Angeles | 1 | 1 |
| Payette River Mines | 101654 | — | 0 | 0 |
| Peak Oil Tool | 101655 | Loma | 5 | 1 |
| Pearl Montana E&P LTD | 101656 | Calgary | 2 | 1 |
| Pease Oil & Gas Company | 101657 | Grand Junction | 48 | 5 |
| Pease, R W | 101658 | — | 1 | 1 |
| Pease, Willard H | 101659 | Grand Junction | 7 | 2 |
| Peay, Edwin A Jr | 101660 | — | 1 | 1 |
| Peerless Oil Company | 101661 | — | 1 | 1 |
| Pel-Star Energy | 101662 | Dallas | 0 | 0 |
| Pendragon Energy Partners Inc | 101663 | Lakewood | 10 | 2 |
| Pennzenergy Company | 101664 | Houston | 0 | 0 |