| Alleder Inc. |
013296 |
| Apache Corporation |
027200 |
| Bettis, Boyle & Stovall |
068360 |
| Birch Operations, Inc. |
071331 |
| Bolger Operating Co. |
080388 |
| BP America Production Company |
040798 |
| Breck Operating Corp. |
089974 |
| Breitburn Operating L.P. |
090732 |
| Bta Oil Producers, LLC |
041867 |
| Burleson Petroleum, Inc. |
109255 |
| Byrd Operating Company |
118748 |
| Callon Petroleum Operating Co |
124828 |
| Cambrian Management, LTD. |
126758 |
| Carlow Corp. |
132340 |
| Chevron Midcontinent, L.P. |
147862 |
| Chevron U. S. A. Inc. |
148113 |
| Citation Oil & Gas Corp. |
154235 |
| Cog Operating LLC |
166150 |
| Conocophillips Company |
172232 |
| Crownquest Operating, LLC |
191554 |
| De3 Operating LLC |
518310 |
| Desert Production, Inc. |
216556 |
| Devon Energy Production Co, L.P. |
216378 |
| Diamondback E&P LLC |
217012 |
| Discovery Operating, Inc. |
220865 |
| Earthstone Operating, LLC |
238732 |
| E.G.L. Resources, Inc. |
238522 |
| Encana Oil & Gas(USA) Inc. |
251691 |
| Endeavor Energy Resources L.P. |
251726 |
| Energen Resources Corporation |
252002 |
| E R Operating Company |
238075 |
| Fasken Oil And Ranch, LTD. |
263696 |
| FDL Operating, LLC |
263924 |
| Fivestones Energy LLC |
271567 |
| Floyd, Timber Inc. |
274426 |
| G P II Energy, Inc. |
292232 |
| Great Western Drilling Company |
328780 |
| Hamman Oil & Refining Company |
350200 |
| Henry Resources LLC |
378535 |
| Hunt Oil Company |
416330 |
| Independence Resources MGMT, LLC |
423716 |
| JM Cox Resources, L.P. |
433075 |
| Kaiser-Francis Oil Company |
450175 |
| Lario Oil & Gas Company |
486710 |
| L.C.S. Production Company |
479574 |
| Legacy Reserves Operating LP |
495445 |
| Maverick Operating, LLC |
534209 |
| Merit Energy Company |
561136 |
| Mexco Energy Corporation |
562563 |
| Midland Energy, Inc. |
565460 |
| Mid-States Operating Company |
566121 |
| Momentum Energy Corporation |
574315 |
| Momentum Operating Co., Inc. |
574324 |
| Mulloy Operating, Inc. |
593077 |
| Murchison Oil & Gas Inc |
593920 |
| MWS Producing, Inc. |
597379 |
| Naumann Oil & Gas, Inc. |
601025 |
| Northstar Operating Company |
614609 |
| Occidental Permian LTD. |
617544 |
| O'Neill Properties, LTD. |
623700 |
| Oxy USA Inc. |
630591 |
| Oxy USA WTP LP |
630555 |
| Parsley Energy Operations, LLC |
642652 |
| Pbex Operations, LLC |
630732 |
| Ped Oil Corporation |
649480 |
| Permian Deep Rock Oil Co., LLC |
655805 |
| Petroplex Energy Inc. |
660886 |
| Pioneer Natural Res. USA, Inc. |
665748 |
| Pitts Energy Co. |
666430 |
| Platform Operating, LLC |
667928 |
| Prasad, Hari Production Co. |
675948 |
| Prime Operating Company |
677770 |
| Purvis Operating Co. |
683200 |
| Ramtex Energy LLC |
690225 |
| Relentless Permian Operating LLC |
700976 |
| Robertson Resources, Inc. |
718770 |
| RP Operating, L.L.C. |
732229 |
| RSP Permian, LLC |
732224 |
| SM Energy Company |
788997 |
| Snow Oil & Gas Inc. |
798635 |
| Southwest Royalties, Inc. |
806470 |
| Summit Petroleum LLC |
829221 |
| Tacor Resources Inc |
834330 |
| Tamarack Petroleum Company, Inc. |
835630 |
| Texon Oil Company, Inc. |
850648 |
| Thompson, J. Cleo |
855610 |
| Trilogy Operating, Inc. |
869713 |
| Vanguard Operating, LLC |
881585 |
| Vaquero Hunter Inc. |
882761 |
| V-F Petroleum Inc. |
880375 |
| WTG Exploration |
945220 |
| XTO Energy Inc. |
945936 |