| 501 | Future Energy Corp | Zanesville, OH 43701 | Oil & Gas Operator | Dec 1991 |
| 502 | Future Production Inc | Canton, OH 44708 | Oil & Gas Operator | Dec 2023 |
| 503 | G & O Resources LTD | Akron, OH 44311 | Oil & Gas Operator | Dec 2020 |
| 504 | G & S Oil & Gas Inc | Parkersburg, WV 26101-5762 | Oil & Gas Operator | Dec 2015 |
| 505 | G W F Corporation | Columbus, OH 43215 | Oil & Gas Operator | Dec 2003 |
| 506 | G-D Oil & Gas Partnership | N Canton, OH 44721 | Oil & Gas Operator | Dec 2019 |
| 507 | G-R Contracting Inc | Lewisville, OH 43754 | Oil & Gas Operator | Dec 2024 |
| 508 | G-R-F Energy, Inc | Kenton, OH 43326 | Oil & Gas Operator | Dec 1994 |
| 509 | Gaia Exploration LLC | Cumberland, OH 43732-9760 | Oil & Gas Operator | Dec 2023 |
| 510 | Gallwitz Ray Stephen | Walhonding, OH 43843 | Oil Operator | Dec 2024 |
| 511 | Gao Holdings Inc | Cortland, OH 44410 | Oil & Gas Operator | Dec 2024 |
| 512 | Garver Oil LLC | Mansfield, OH 44907 | Oil & Gas Operator | Dec 2022 |
| 513 | Gas & Oil Pipe Supply | Millersburg, OH 44654 | Oil & Gas Operator | Dec 2006 |
| 514 | Gas Acquisition Co LTD | Akron, OH 44308 | Oil & Gas Operator | Dec 2017 |
| 515 | Gas Enterprise Company Inc | Wingett Run, OH 45789 | Oil & Gas Operator | Dec 2024 |
| 516 | Gasearch Inc | Girard, OH 44420 | Oil & Gas Operator | Dec 1985 |
| 517 | Ge Consumer & Industrial | Louisville, KY 40225 | Oil & Gas Operator | Dec 2006 |
| 518 | Geitgey Donald W Jr | N Canton, OH 44721 | Oil & Gas Operator | Dec 2024 |
| 519 | Gemak Exp Inc | Dayton, OH 45414 | Oil Operator | Dec 1998 |
| 520 | Genesis Resources LLC | Parkersburg, WV 26104 | Oil & Gas Operator | Dec 2019 |
| 521 | Geo Energy Inc | Dublin, OH 43017 | Oil & Gas Operator | Dec 1989 |
| 522 | Geo Kat LLC | Millersport, OH 43046 | Oil & Gas Operator | Dec 2024 |
| 523 | Geopetro Inc | Worthington, OH 43085 | Oil & Gas Operator | Dec 1994 |
| 524 | Geopetro LLC | Worthington, OH 43085-2316 | Oil & Gas Operator | Dec 2025 |
| 525 | George W Plant Drilling | Corning, OH 43730 | Oil Operator | Dec 2024 |
| 526 | Geostrata Inc | Chagrin Falls, OH 44022 | Oil & Gas Operator | Dec 1993 |
| 527 | Giant Petroleum Corp | Jefferson, OH 44047 | Oil & Gas Operator | Dec 1990 |
| 528 | Gilbert Oil Co | Ravenna, OH 44266 | Oil & Gas Operator | Dec 1988 |
| 529 | Gilmour Academy Corp | Gates Mills, OH 44040 | Oil & Gas Operator | Dec 2024 |
| 530 | Gingerich Mike | McConnelsville, OH 43756 | Oil & Gas Operator | Dec 2010 |
| 531 | Glacier Energy Corp | Bellevue, WA 98004 | Oil & Gas Operator | Dec 1991 |
| 532 | Gleneayre Resources Inc | Reno, OH 45773 | Oil & Gas Operator | Dec 1990 |
| 533 | GM/Delphi Packard Elec. | Warren, OH 44486 | Oil & Gas Operator | Dec 1995 |
| 534 | Go-Jo Industries Inc | Akron, OH 44311 | Oil & Gas Operator | Dec 1998 |
| 535 | Goehler Oil & Gas LLC | Cortland, NY 13045 | Oil & Gas Operator | Dec 2021 |
| 536 | Gomez Stella M | Warsaw, OH 43844 | Oil & Gas Operator | Dec 2010 |
| 537 | Gonzoil Inc | Canton, OH 44718-1806 | Oil & Gas Operator | Dec 2018 |
| 538 | Goodyear Tire & Rubber | Akron, OH 44316 | Oil & Gas Operator | Dec 2008 |
| 539 | Gordon Energy Corp | Woodsfield, OH 43793 | Oil & Gas Operator | Dec 1991 |
| 540 | Gormley Joseph A | Zanesville, OH 43701 | Oil & Gas Operator | Dec 2018 |
| 541 | Gossett, Henry O., Jr. | Longview, TX 75606 | Oil & Gas Operator | Dec 2001 |
| 542 | Gradall Co | New Philadelphi, OH 44663 | Oil & Gas Operator | Dec 2024 |
| 543 | Graham-Michaelis Corporation | Wichita, KS 67201 | Oil & Gas Operator | Dec 2010 |
| 544 | Grassbaugh WM & Carol | Glenmont, OH 44628 | Oil & Gas Operator | Dec 2024 |
| 545 | Graymarr LLC | Graysville, OH 45734 | Oil & Gas Operator | Dec 2024 |
| 546 | Great Plains Exploration LLC | Mentor, OH 44060 | Oil & Gas Operator | Dec 2016 |
| 547 | Green Circle Growers, Inc. | Oberlin, OH 44074-9465 | Gas Operator | Dec 2008 |
| 548 | Green Energy Inc | Wooster, OH 44691 | Oil & Gas Operator | Dec 2024 |
| 549 | Green Gas Co | Wooster, OH 44691 | Oil & Gas Operator | Dec 2020 |
| 550 | Greenbrier Energy Inc | Marietta, OH 45750 | Oil & Gas Operator | Dec 2024 |
| 551 | Greenland Petroleum Co | Belle Valley, OH 43717 | Oil & Gas Operator | Dec 1991 |
| 552 | Greenwood James W | New Matamoras, OH 45767 | Oil & Gas Operator | Dec 2014 |
| 553 | Greenwood Oil LLC | Marietta, OH 45750 | Oil & Gas Operator | Dec 2024 |
| 554 | Greenwood Oil R F D | Warsaw, OH 43844 | Oil & Gas Operator | Dec 1990 |
| 555 | Gregg Price Corp | Dover, OH 44622 | Oil & Gas Operator | Dec 2014 |
| 556 | Gress Oil & Gas | Coshocton, OH 43812 | Oil & Gas Operator | Dec 2024 |
| 557 | Grim Paul A | Logan, OH 43138-9445 | Oil & Gas Operator | Dec 2020 |
| 558 | Grimsby Exploration Inc | Canton, OH 44709 | Oil & Gas Operator | Dec 2018 |
| 559 | Group Maintenance Corp | Jefferson, OH 44047 | Oil & Gas Operator | Dec 2012 |
| 560 | Guardian Management Inc | Marion, OH 43302 | Oil & Gas Operator | Dec 1997 |
| 561 | Guernsey Petroleum Corporation | Atlanta, GA 30318 | Oil & Gas Operator | Nov 1997 |
| 562 | Gulfport Appalachia LLC | Oklahoma City, OK 73114-2640 | Oil & Gas Operator | Sep 2025 |
| 563 | Gulfport Energy Corporation | Oklahoma City, OK 73114-5003 | Oil & Gas Operator | Aug 2025 |
| 564 | GWB Oil & Gas LLC | Marietta, OH 45750 | Oil & Gas Operator | Dec 2024 |
| 565 | H & A Drilling | Newark, OH 43056 | Oil Operator | Dec 2024 |
| 566 | H & D Drilling Co Inc | Frazeysburg, OH 43822 | Oil & Gas Operator | Dec 2024 |
| 567 | H & H Energy Of Ohio LTD | Zanesville, OH 43701 | Oil & Gas Operator | Dec 2024 |
| 568 | H & H Producing | Wadsworth, OH 44281 | Oil & Gas Operator | Dec 1993 |
| 569 | H & K Energy Corp | Columbus, OH 43229 | Oil & Gas Operator | Dec 1991 |
| 570 | H & S Drilling Co Inc | Frazeysburg, OH 43822 | Oil & Gas Operator | Dec 2016 |
| 571 | H & S Operating Company Inc | Winesburg, OH 44690 | Oil & Gas Operator | Dec 2024 |
| 572 | H & W Drilling Inc | Racine, OH 45769 | Oil & Gas Operator | Dec 2023 |
| 573 | H & W Energy | Youngstown, OH 44512 | Oil & Gas Operator | Dec 2015 |
| 574 | H I Smith Oil & Gas Inc | Holmesville, OH 44633 | Oil & Gas Operator | Dec 2024 |
| 575 | H L Altier Service Co Inc | Canton, OH 44718-3752 | Oil & Gas Operator | Dec 2013 |
| 576 | H. C. Oil Co. | Weatherford, TX 76085 | Oil & Gas Operator | Feb 2026 |
| 577 | Haddad & Brooks Inc | Washington, PA 15301 | Oil & Gas Operator | Dec 2018 |
| 578 | Haessly Hardwood Lumber Inc | Marietta, OH 45750 | Oil & Gas Operator | Dec 2024 |
| 579 | Halcon Operating Co., Inc. | Houston, TX 77024 | Oil & Gas Operator | Feb 2026 |
| 580 | Hall & Horning Serv Inc | Atwater, OH 44201-9375 | Oil & Gas Operator | Dec 2009 |
| 581 | Hall Drilling LLC (Oil & Gas) | Ellenboro, WV 26346 | Gas Operator | Sep 2014 |
| 582 | Hall Energy Inc | Magnetic Spring, OH 43036 | Oil & Gas Operator | Dec 2017 |
| 583 | Hall IVan & Assoc Inc | Berea, OH 44017 | Oil & Gas Operator | Dec 1997 |
| 584 | Hall Thomas E | Marietta, OH 45750 | Oil & Gas Operator | Dec 2021 |
| 585 | Halter Ralph P | Robertsville, OH 44670 | Oil Operator | Dec 1999 |
| 586 | Hamblin Ralph Inc | MT Vernon, OH 43050 | Oil & Gas Operator | Dec 1991 |
| 587 | Hamilton Leonard O | Marietta, OH 45750 | Oil & Gas Operator | Dec 2024 |
| 588 | Hanger Marvin | Vincent, OH 45784 | Oil & Gas Operator | Dec 2024 |
| 589 | Hanna M A Co | Cleveland, OH 44114-1824 | Oil & Gas Operator | Dec 1991 |
| 590 | Hardco Inc | Cleveland, OH 44115 | Oil & Gas Operator | Dec 1992 |
| 591 | Hardesty Production | Gambier, OH 43022 | Oil & Gas Operator | Dec 2024 |
| 592 | Hardin Hanley E | Zanesville, OH 43701 | Oil & Gas Operator | Dec 1995 |
| 593 | Harley Drilling & Producing LTD | Burbank, OH 44214 | Oil & Gas Operator | Dec 2024 |
| 594 | Harmon O G LLC | Graysville, OH 45734 | Oil & Gas Operator | Dec 2024 |
| 595 | Harmons Well Service | Graysville, OH 45734 | Oil & Gas Operator | Dec 2019 |
| 596 | Harnetty Francis Dba Harnetty Oil & Gas | Junction City, OH 43748 | Oil & Gas Operator | Dec 2019 |
| 597 | Harris Engineering Co | Dallas, TX 75248 | Oil & Gas Operator | Dec 1996 |
| 598 | Harrison Energy | Tippecanoe, OH 44699 | Oil & Gas Operator | Dec 2000 |
| 599 | Hatco Productions LTD | North Augusta, SC 29860 | Oil Operator | Dec 2024 |
| 600 | Hawke Inc | Barbertib, OH 44203 | Oil & Gas Operator | Dec 2024 |