| 1 | L P C Energy, Inc. | | Oil & Gas Operator | Mar 1985 |
| 2 | L&N DRLG Co&K.D. Lankford, Jr | | Gas Operator | Aug 2006 |
| 3 | L'Oil Operating & Management Co., Inc. | | Oil & Gas Operator | Nov 2024 |
| 4 | L'Oil Operating And MGMT. Co. | | Oil & Gas Operator | Dec 2008 |
| 5 | L. D. McMullan | | Oil Operator | Jun 2023 |
| 6 | L. E. Hester | | Gas Operator | Oct 2004 |
| 7 | L. R. Resources II | | Oil & Gas Operator | Feb 1991 |
| 8 | La. Fete Oil & Gas, Inc. | | Oil & Gas Operator | May 1995 |
| 9 | La. Gas Production, L.C. | | Gas Operator | Sep 2018 |
| 10 | La. Land & Expl. Co. | | Oil & Gas Operator | Dec 2010 |
| 11 | Lahoma Gas Company | | Gas Operator | Dec 1980 |
| 12 | Lankford & Nance | | Gas Operator | Dec 2010 |
| 13 | Laster Welding And Well Serv, Inc. | | Gas Operator | Jul 2020 |
| 14 | Latex Petroleum Corp. | Houston, TX 77090 | Oil & Gas Operator | Aug 2012 |
| 15 | Lear Gas Transmission | | Oil Operator | Aug 1989 |
| 16 | Lear Petroleum Exploration Inc | Dallas, TX 75206 | Oil & Gas Operator | Aug 1999 |
| 17 | Legacy Energy LLC | Russell, KS 67665 | Oil Operator | Jan 2025 |
| 18 | Linville Natural Gas Co. Inc. | | Gas Operator | Sep 2000 |
| 19 | Long Oil & Natural Gas Corp. | | Oil & Gas Operator | Feb 1996 |
| 20 | Lotter Gas Co., Inc. | | Gas Operator | Apr 2009 |
| 21 | Louisiana Crude Oil&Gas Co Inc | | Oil & Gas Operator | Mar 1984 |
| 22 | Louisiana Gas Production Co | | Gas Operator | Dec 1996 |
| 23 | Louisiana Operating Co., Inc. | | Oil & Gas Operator | Aug 1994 |
| 24 | Luffey Gas Corp. | | Gas Operator | Dec 2008 |
| 25 | Luffey Gas Corp.-Graff | | Gas Operator | Oct 1994 |
| 26 | Luffey-Stinson Gas Corporation | | Gas Operator | Sep 2018 |