| 1 | L & T Exploration | | Oil & Gas Operator | Dec 1987 |
| 2 | L E Carpenter Oil & Gas, Inc. | | Oil & Gas Operator | Sep 1985 |
| 3 | La Mesa Production, Inc. | | Oil & Gas Operator | Apr 2004 |
| 4 | Ladd Petroleum Corp. | Denver, CO 80202 | Oil & Gas Operator | Oct 2004 |
| 5 | Lakeside Resources | | Oil & Gas Operator | Mar 1989 |
| 6 | Lamson Petroleum Corporation | | Oil & Gas Operator | Mar 1993 |
| 7 | Lamson/Crocker Petroleum Corp. | | Oil & Gas Operator | May 1988 |
| 8 | Lamson/Onshore Petroleum Corp. | | Oil & Gas Operator | Sep 1985 |
| 9 | Lancer Resources Company | | Oil & Gas Operator | Jan 1998 |
| 10 | Las Services, Inc. | | Oil & Gas Operator | Oct 1997 |
| 11 | Latex Petroleum Corp. | Houston, TX 77090 | Oil & Gas Operator | Aug 2012 |
| 12 | Laurel Operating Company, Inc. | Stillwater, OK 74074-3025 | Oil & Gas Operator | Jun 2025 |
| 13 | Lea Exploration, Inc. | | Oil & Gas Operator | Nov 1989 |
| 14 | Lear Petroleum Exploration Inc | Dallas, TX 75206 | Oil & Gas Operator | Aug 1999 |
| 15 | Legendary Oil Co., Inc. | | Oil Operator | Feb 2004 |
| 16 | Leger Production Company, Inc. | | Oil & Gas Operator | Apr 1984 |
| 17 | Liberty Oil And Gas Corp. | Olney, IL 62450-2489 | Oil & Gas Operator | Dec 2021 |
| 18 | Linder Oil Company | | Oil & Gas Operator | Apr 1985 |
| 19 | Linder Oil Company,A Partnership | Shreveport, LA 71136 | Oil & Gas Operator | Oct 2025 |
| 20 | Llog Expl. Co. | Metairie, LA 70005 | Oil & Gas Operator | Jan 2003 |
| 21 | Louisiana Crude Oil&Gas Co Inc | | Oil & Gas Operator | Mar 1984 |
| 22 | Louisiana Gas System, Inc. | | Oil Operator | Apr 2004 |
| 23 | Louisiana Intrastate Gas Corp. | | Oil Operator | Feb 1994 |
| 24 | Louisiana Jordan Oil Co, Inc. | Lake Charles, LA 70602 | Oil & Gas Operator | Dec 2024 |
| 25 | Louisiana Tank, Inc. | | Oil Operator | Mar 2023 |
| 26 | Lucky Lad Energy, LLC | Magnolia, TX 77353 | Oil & Gas Operator | Oct 2025 |
| 27 | Lyco Energy Corporation | Dallas, TX 75206 | Oil & Gas Operator | Jun 2015 |
| 28 | Lyn-Que Oil & Gas, Inc. | | Oil Operator | Sep 1992 |
| 29 | Lynal, Inc. | | Oil & Gas Operator | Oct 1988 |
| 30 | Lynal, Inc.- Michel T Halbouty | | Oil & Gas Operator | Oct 1984 |
| 31 | Lyons Petroleum, Inc. | | Oil & Gas Operator | Oct 1988 |