| 6601 | Yarberry Oil Company | Wichita Falls, TX 76308-5120 | Oil & Gas Operator | Apr 2015 |
| 6602 | Yarbrough R E | Lago VIsta, TX 78645-0005 | Oil & Gas Operator | Mar 2015 |
| 6603 | Yarhola Production Company | Drumright, OK 74030-0693 | Oil & Gas Operator | Jan 2024 |
| 6604 | Yates Oil | Pawhuska, OK 74056 | Oil Operator | Mar 2015 |
| 6605 | Yegen E C | Casper, WY 82604 | Oil & Gas Operator | Mar 2015 |
| 6606 | Yerby Bill | Ada, OK 74820-5404 | Oil Operator | Jan 2012 |
| 6607 | Yeubanks Barbara | Cromwell, OK 74837-0059 | Oil Operator | Jan 2024 |
| 6608 | Yingling Oil, Inc. | Oklahoma City, OK 73118 | Oil & Gas Operator | Dec 2000 |
| 6609 | Yocham Harlan E. | Sapulpa, OK 74066 | Oil Operator | Aug 2013 |
| 6610 | Young H Inc | Edmond, OK 73013 | Oil & Gas Operator | Oct 1993 |
| 6611 | Young Marshall R Oil Co | Fort Worth, TX 76107 | Oil & Gas Operator | Mar 2011 |
| 6612 | Young Resources, Inc. | Fort Worth, TX 76102 | Oil & Gas Operator | Aug 1999 |
| 6613 | Young Tommy Oil Inc | Woodward, OK 73802-0893 | Oil & Gas Operator | Dec 2023 |
| 6614 | Young Z Joe | Cement, OK 73017-0600 | Oil & Gas Operator | Mar 2015 |
| 6615 | Young Zoral J | Cement, OK 73017-0663 | Oil & Gas Operator | Sep 2000 |
| 6616 | Young, John H., Inc. | Houston, TX 77027 | Oil & Gas Operator | Apr 2024 |
| 6617 | Youngblood J Lee | Dallas, TX 75221 | Oil & Gas Operator | Feb 1996 |
| 6618 | Younger Enterprises Inc | Ada, OK 74821-1882 | Oil Operator | Jan 2003 |
| 6619 | Z G Operating LLC | Oklahoma City, OK 73134-5038 | Oil & Gas Operator | Nov 2009 |
| 6620 | Z G Exploration Inc | Oklahoma City, OK 73112 | Oil & Gas Operator | Feb 2005 |
| 6621 | Zafar Oil & Gas, Inc. | Oklahoma City, OK 73132 | Oil Operator | Aug 2013 |
| 6622 | Zap Oil Company | Nowata, OK 74048-2640 | Oil & Gas Operator | Nov 2005 |
| 6623 | Zarvona Energy LLC | Houston, TX 77002 | Oil & Gas Operator | Apr 2024 |
| 6624 | Zca Gas Gathering Co., Inc. | Bartlesville, OK 74003 | Oil & Gas Operator | Apr 2020 |
| 6625 | Zeal Production Company | | Oil & Gas Operator | Jan 2024 |
| 6626 | Zeiders Bros Oil & Gas Co LLC | Edmond, OK 73003 | Oil & Gas Operator | Dec 2023 |
| 6627 | Zenergy Inc | Tulsa, OK 74136 | Oil & Gas Operator | Jan 2024 |
| 6628 | Zenith Oil & Gas, LLC | Kilgore, TX 75663 | Oil & Gas Operator | Dec 2023 |
| 6629 | Zephyr Operating Co LLC | Oklahoma City, OK 73118-6035 | Oil & Gas Operator | Jan 2024 |
| 6630 | Zephyr SWD LLC | | Oil Operator | Dec 2023 |
| 6631 | Zielke Contracting LLC | Balko, OK 73931-1187 | Oil Operator | Jun 2020 |
| 6632 | Zilkha Energy Company | Houston, TX 77046 | Oil & Gas Operator | Oct 2002 |
| 6633 | Zim Energy Corporation | Tulsa, OK 74153 | Oil & Gas Operator | Jan 1998 |
| 6634 | Zimet Brothers Inc | | Oil Operator | Mar 2008 |
| 6635 | Zimtex Energy LLC | | Oil & Gas Operator | Nov 2017 |
| 6636 | Zinke & Trumbo LTD | Tulsa, OK 74105 | Oil & Gas Operator | Sep 2017 |
| 6637 | Zion Energy Corporation | Peru, KS 67360-0082 | Oil Operator | Aug 2000 |
| 6638 | Zollinger Veldon | Cresent, OK 73028 | Oil & Gas Operator | Apr 2009 |
| 6639 | Zollinger Veldon Inc | Crescent, OK 73028-9280 | Oil & Gas Operator | Nov 2018 |
| 6640 | ZP Disposal Systems LLC | Kingfisher, OK 73750-7084 | Oil Operator | Jan 2024 |
| 6641 | Zuhone William H | Mattoon, IL 61938-4019 | Oil & Gas Operator | Jan 2015 |
| 6642 | Zumyers Inc | Newalla, OK 74857-0259 | Oil Operator | Apr 2003 |
| 6643 | ZZ Energy LLC | Norman, OK 73070-4531 | Gas Operator | Dec 2023 |
| 6644 | Zzron Inc. | Midland, TX 79704 | Oil & Gas Operator | Aug 2003 |