| 456693 | Dec 23, 1996 | Dec 23, 1996 | Costilla Petroleum Corporation | Howard | Ziffle Fred 35 #2 | 9,000 | 22735108 |
| 456692 | Dec 23, 1996 | Dec 23, 1996 | Costilla Petroleum Corporation | Howard | McCrary 45 #1 | 9,000 | 22735111 |
| 456689 | Dec 23, 1996 | Dec 23, 1996 | Costilla Petroleum Corporation | Howard | Fryar 47 #1 | 9,000 | 22735109 |
| 456688 | Dec 23, 1996 | Dec 23, 1996 | Costilla Petroleum Corporation | Howard | Christian 48 #1 | 9,000 | 22735110 |
| 455797 | Dec 3, 1996 | Dec 3, 1996 | Costilla Petroleum Corporation | Live Oak | Gorbel G.U. #7 | 11,300 | 29733495 |
| 454009 | Nov 26, 1996 | Nov 26, 1996 | Costilla Petroleum Corporation | Martin | Nail "33" #9 | 10,000 | 31734057 |
| 454008 | Nov 26, 1996 | Nov 26, 1996 | Costilla Petroleum Corporation | Martin | Nail "33" #8 | 10,000 | 31734055 |
| 454007 | Nov 26, 1996 | Nov 26, 1996 | Costilla Petroleum Corporation | Martin | Nail "33" #10 | 10,000 | 31734056 |
| 455619 | Nov 25, 1996 | Nov 25, 1996 | Costilla Petroleum Corporation | Crane | Edwards 22 #2 | 10,500 | 10334453 |
| 455064 | Nov 12, 1996 | Nov 12, 1996 | Costilla Petroleum Corporation | Burleson | Patterson G #1HH | 8,000 | 05133538 |
| 455063 | Nov 12, 1996 | Nov 12, 1996 | Costilla Petroleum Corporation | Limestone | Tucker #4 | 11,000 | 29331174 |
| 453953 | Nov 12, 1996 | Nov 12, 1996 | Costilla Petroleum Corporation | Martin | Glass, George W. 21 #5 | 10,000 | 31734214 |
| 453952 | Nov 12, 1996 | Nov 12, 1996 | Costilla Petroleum Corporation | Martin | Glass, George W. 21 #6 | 10,000 | 31734053 |
| 453896 | Nov 12, 1996 | Nov 12, 1996 | Costilla Petroleum Corporation | Martin | Glass, George W. 24 #8 | 10,000 | 31734050 |
| 453894 | Nov 12, 1996 | Nov 12, 1996 | Costilla Petroleum Corporation | Martin | Glass, George W. 24 #9 | 10,000 | 31734049 |
| 453892 | Nov 12, 1996 | Nov 12, 1996 | Costilla Petroleum Corporation | Martin | Glass, George W. 24 #7 | 10,000 | 31734051 |
| 454938 | Nov 8, 1996 | Nov 8, 1996 | Costilla Petroleum Corporation | Andrews | North Block 12 #11 | 13,000 | 00338061 |
| 454671 | Nov 1, 1996 | Nov 1, 1996 | Costilla Petroleum Corporation | Howard | Douglas, Olive "39" #1 | 9,000 | 22735088 |
| 454670 | Nov 1, 1996 | Nov 1, 1996 | Costilla Petroleum Corporation | Howard | Ziffle, Arnold #3 | 9,000 | 22735087 |
| 453893 | Oct 15, 1996 | Oct 15, 1996 | Costilla Petroleum Corporation | Martin | Nail #3307 | 10,000 | 31734052 |
| 453384 | Oct 2, 1996 | Oct 2, 1996 | Costilla Petroleum Corporation | Crane | Edwards "22" #1 | 10,500 | 10334447 |
| 453383 | Oct 2, 1996 | Oct 2, 1996 | Costilla Petroleum Corporation | Crane | Edwards "14" #2 | 10,500 | 10334446 |
| 452329 | Oct 1, 1996 | Oct 1, 1996 | Costilla Petroleum Corporation | Howard | Rowland "34" #4 | 9,000 | 22735069 |
| 452134 | Sep 26, 1996 | Sep 26, 1996 | Costilla Petroleum Corporation | Howard | Rowland "34" #2 | 9,000 | 22735067 |
| 452865 | Sep 18, 1996 | Sep 18, 1996 | Costilla Petroleum Corporation | Crane | Edwards 14 #1 | 9,200 | 10334394 |
| 452864 | Sep 18, 1996 | Sep 18, 1996 | Costilla Petroleum Corporation | Crane | Gary "36" #1 | 10,500 | 10334441 |
| 452742 | Sep 17, 1996 | Sep 17, 1996 | Costilla Petroleum Corporation | Andrews | North Block 12 #10 | 11,500 | 00337987 |
| 452135 | Sep 12, 1996 | Sep 12, 1996 | Costilla Petroleum Corporation | Howard | Rowland "34" #3 | 9,000 | 22735068 |
| 451829 | Aug 22, 1996 | Aug 22, 1996 | Costilla Petroleum Corporation | Howard | EB 37 #1 | 9,000 | 22735066 |
| 451828 | Aug 22, 1996 | Aug 22, 1996 | Costilla Petroleum Corporation | Howard | Lou Ann 6 #2 | 11,000 | 22735065 |
| 451434 | Aug 21, 1996 | Aug 21, 1996 | Costilla Petroleum Corporation | Limestone | Tucker #3 | 11,000 | 29331160 |
| 451563 | Aug 16, 1996 | Aug 16, 1996 | Costilla Petroleum Corporation | Bee | Sugarek, L. D. #3 | 4,000 | 02532783 |
| 451323 | Aug 8, 1996 | Aug 8, 1996 | Costilla Petroleum Corporation | Howard | Davis "5" #1 | 11,000 | 22735060 |
| 451322 | Aug 8, 1996 | Aug 8, 1996 | Costilla Petroleum Corporation | Howard | Rowland "34" #1 | 9,000 | 22735059 |
| 451322Amendment | Aug 8, 1996 | Aug 8, 1996 | Costilla Petroleum Corporation | Howard | Rowland "34" #1 | 9,000 | 22735059 |
| 451321 | Aug 8, 1996 | Aug 8, 1996 | Costilla Petroleum Corporation | Howard | Coconut "10" #1 | 11,000 | 22735058 |
| 451041 | Aug 6, 1996 | Aug 6, 1996 | Costilla Petroleum Corporation | Lavaca | Robertson F #4 | 5,380 | 28531747 |
| 450848 | Jul 26, 1996 | Jul 26, 1996 | Costilla Petroleum Corporation | Sutton | Whitehead 2 #202 | 9,000 | 43534609 |
| 450847 | Jul 26, 1996 | Jul 26, 1996 | Costilla Petroleum Corporation | Sutton | Whitehead 8 #802 | 9,000 | 43534608 |
| 450713 | Jul 23, 1996 | Jul 23, 1996 | Costilla Petroleum Corporation | Howard | Drucker, Sam 36 #1 | 9,000 | 22735056 |
| 450712 | Jul 23, 1996 | Jul 23, 1996 | Costilla Petroleum Corporation | Howard | Clyde 45 #1 | 9,000 | 22735055 |
| 450277 | Jul 12, 1996 | Jul 12, 1996 | Costilla Petroleum Corporation | Crane | Crane "O" Fee #1 | 10,500 | 10334432 |
| 450276 | Jul 12, 1996 | Jul 12, 1996 | Costilla Petroleum Corporation | Crane | Crane "N" Fee #1 | 10,500 | 10334431 |
| 449840 | Jun 28, 1996 | Jun 28, 1996 | Costilla Petroleum Corporation | Crane | Glass "32-H" #8 | 4,500 | 10333079 |
| 449089 | Jun 10, 1996 | Jun 10, 1996 | Costilla Petroleum Corporation | Crane | Glass "32-A" #7 | 4,500 | 10333136 |
| 448559 | May 24, 1996 | May 24, 1996 | Costilla Petroleum Corporation | Crane | Edwards 12 #1 | 9,500 | 10334286 |
| 446729 | May 23, 1996 | May 23, 1996 | Costilla Petroleum Corporation | Bee | Fox "D" #1 | 5,132 | 02532286 |
| 448393 | May 21, 1996 | May 21, 1996 | Costilla Petroleum Corporation | Crane | University 30-1 #1 | 9,000 | 10334429 |
| 448393Amendment | May 21, 1996 | May 21, 1996 | Costilla Petroleum Corporation | Crane | University 30-1 #1 | 9,999 | 10334429 |
| 447626 | May 20, 1996 | May 20, 1996 | Costilla Petroleum Corporation | Limestone | Tucker #2 | 11,200 | 29331142 |
| 447606 | May 3, 1996 | May 3, 1996 | Costilla Petroleum Corporation | Live Oak | Goebel Gas Unit #9 | 8,300 | 29733914 |
| 447181 | Apr 18, 1996 | Apr 18, 1996 | Costilla Petroleum Corporation | Tom Green | Robertson, John D. C #28HH | 5,500 | 45132044 |
| 447181Amendment | Apr 18, 1996 | Apr 18, 1996 | Costilla Petroleum Corporation | Tom Green | Robertson, John D. C #28HH | 4,950 | 45132044 |
| 447164 | Apr 17, 1996 | Apr 17, 1996 | Costilla Petroleum Corporation | Howard | Kimble 28 #1 | 9,000 | 22735033 |
| 446100 | Mar 20, 1996 | Mar 20, 1996 | Costilla Petroleum Corporation | Crane | Crane "L" Fee #1 | 9,000 | 10334411 |
| 445439 | Mar 1, 1996 | Mar 1, 1996 | Costilla Petroleum Corporation | Ector | Blakeney B. H. G #1Q | 4,000 | 13511235 |
| 444186 | Feb 13, 1996 | Feb 13, 1996 | Costilla Petroleum Corporation | Crane | Glass "32-H" #4 | 4,500 | 10334398 |
| 444183 | Feb 13, 1996 | Feb 13, 1996 | Costilla Petroleum Corporation | Crane | Glass "32-A" #06 | 4,500 | 10334399 |
| 444555 | Feb 7, 1996 | Feb 7, 1996 | Costilla Petroleum Corporation | Howard | Christian 47 #2 | 9,000 | 22734998 |
| 444543 | Feb 6, 1996 | Feb 6, 1996 | Costilla Petroleum Corporation | Crane | Glass "32-A" #3 | 4,500 | 10334405 |
| 444542 | Feb 6, 1996 | Feb 6, 1996 | Costilla Petroleum Corporation | Howard | Ziffle, Arnold #2 | 9,000 | 22734996 |
| 444541 | Feb 6, 1996 | Feb 6, 1996 | Costilla Petroleum Corporation | Howard | Ziffle, Fred #1 | 9,000 | 22734997 |
| 444383 | Feb 5, 1996 | Feb 5, 1996 | Costilla Petroleum Corporation | Howard | Hamlin 29 #01 | 9,000 | 22734994 |
| 444383Amendment | Feb 5, 1996 | Feb 5, 1996 | Costilla Petroleum Corporation | Howard | Hamlin 29 #01 | 11,000 | 22734994 |
| 443479 | Jan 5, 1996 | Jan 5, 1996 | Costilla Petroleum Corporation | Crane | Edwards 14 #1 | 13,750 | 10334394 |
| 442433 | Dec 1, 1995 | Dec 1, 1995 | Costilla Petroleum Corporation | Crane | Glass 32 #2 | 4,500 | 10334382 |
| 442433Amendment | Dec 1, 1995 | Dec 1, 1995 | Costilla Petroleum Corporation | Crane | Glass 32 - A #2 | 4,500 | 10334382 |
| 442179 | Nov 22, 1995 | Nov 22, 1995 | Costilla Petroleum Corporation | Howard | Haney Mr. 38 #1 | 9,000 | 22734971 |
| 441408 | Oct 31, 1995 | Oct 31, 1995 | Costilla Petroleum Corporation | Howard | Ziffle, Arnold #1 | 9,950 | 22734954 |
| 440886 | Oct 16, 1995 | Oct 16, 1995 | Costilla Petroleum Corporation | Sterling | McDonald "Eieio" #1 | 8,000 | 43132806 |
| 440469 | Oct 2, 1995 | Oct 2, 1995 | Costilla Petroleum Corporation | Howard | Hamlin 20 #1 | 9,000 | 22734949 |
| 440468 | Oct 2, 1995 | Oct 2, 1995 | Costilla Petroleum Corporation | Howard | Hamlin 18 #1 | 9,000 | 22734950 |
| 439968 | Sep 25, 1995 | Sep 25, 1995 | Costilla Petroleum Corporation | Bee | Sugarek, L. D. #1 | 2,955 | 02531228 |
| 438853 | Aug 14, 1995 | Aug 14, 1995 | Costilla Petroleum Corporation | Howard | Allar-Davis 7 #1 | 11,000 | 22734940 |
| 438772 | Aug 10, 1995 | Aug 10, 1995 | Costilla Petroleum Corporation | Ector | Blakeney, B. H. 'C' #1 Q | 5,000 | 13507768 |
| 438771 | Aug 10, 1995 | Aug 10, 1995 | Costilla Petroleum Corporation | Ector | East Goldsmith San Andres UT 16 #9 | 5,073 | 13534134 |
| 438771Amendment | Aug 10, 1995 | Aug 10, 1995 | Costilla Petroleum Corporation | Ector | East Goldsmith San Andres UT 16 #9 | 5,073 | 13534134 |
| 438695 | Aug 9, 1995 | Aug 9, 1995 | Costilla Petroleum Corporation | Ector | East Goldsmith San Andres 20 #12 | 5,060 | 13507772 |
| 438695Amendment | Aug 9, 1995 | Aug 9, 1995 | Costilla Petroleum Corporation | Ector | East Goldsmith San Andres 20 #12 | 5,060 | 13507772 |
| 438692 | Aug 9, 1995 | Aug 9, 1995 | Costilla Petroleum Corporation | Ector | East Goldsmith San Andres 15 #7 | 5,050 | 13507780 |
| 438690 | Aug 9, 1995 | Aug 9, 1995 | Costilla Petroleum Corporation | Ector | East Goldsmith San Andres 20 #13 | 5,035 | 13507778 |
| 438690Amendment | Aug 9, 1995 | Aug 9, 1995 | Costilla Petroleum Corporation | Ector | East Goldsmith San Andres UT 20 #13 | 5,035 | 13507778 |
| 438336 | Jul 31, 1995 | Jul 31, 1995 | Costilla Petroleum Corporation | Howard | Cobra-Talbot 40 #1 | 9,000 | 22734936 |
| 437228 | Jun 23, 1995 | Jun 23, 1995 | Costilla Petroleum Corporation | Crane | Glass 32 #1 | 5,000 | 10334342 |
| 436709 | Jun 9, 1995 | Jun 9, 1995 | Costilla Petroleum Corporation | Ector | Edwards-TXL Unit #1 | 9,500 | 13537083 |
| 436709Amendment | Jun 9, 1995 | Jun 9, 1995 | Costilla Petroleum Corporation | Ector | Edwards-TXL Unit #1 | 9,500 | 13537083 |
| 433398 | Mar 10, 1995 | Mar 10, 1995 | Costilla Petroleum Corporation | Howard | Watkins 46 #1 | 9,000 | 22734906 |
| 433547 | Mar 8, 1995 | Mar 8, 1995 | Costilla Petroleum Corporation | Howard | Kilpatrick 45 #1 | 9,000 | 22734910 |
| 433539Amendment | Mar 8, 1995 | Mar 8, 1995 | Costilla Petroleum Corporation | Crane | Crane "D" Fee #3 | 9,600 | 10334312 |
| 433539Amendment | Mar 8, 1995 | Mar 8, 1995 | Costilla Petroleum Corporation | Crane | Crane "D" Fee #3 | 9,600 | 10334312 |
| 433359 | Mar 3, 1995 | Mar 3, 1995 | Costilla Petroleum Corporation | Howard | Christian 47 #1 | 9,000 | 22734905 |
| 433160 | Feb 21, 1995 | Feb 21, 1995 | Costilla Petroleum Corporation | Howard | Fuller-Kilpatrick Canyon Unit #1 | 9,000 | 22734903 |
| 431869 | Jan 25, 1995 | Jan 25, 1995 | Costilla Petroleum Corporation | Glasscock | Deventer #2 | 9,000 | 17332481 |
| 430749 | Dec 27, 1994 | Dec 27, 1994 | Costilla Petroleum Corporation | Crane | Edwards 12 #1 | 9,500 | 10334286 |
| 429884 | Nov 15, 1994 | Nov 15, 1994 | Costilla Petroleum Corporation | Howard | Talbot 40 #1 | 9,000 | 22734880 |
| 429884Amendment | Nov 15, 1994 | Nov 15, 1994 | Costilla Petroleum Corporation | Howard | Talbot 40 #1 | 9,000 | 22734880 |
| 428277 | Sep 22, 1994 | Sep 22, 1994 | Costilla Petroleum Corporation | Howard | Bynum "46" #1 | 9,000 | 22734865 |
| 428277Amendment | Sep 22, 1994 | Sep 22, 1994 | Costilla Petroleum Corporation | Howard | Bynum "46" #1 | 9,000 | 22734865 |
| 428053 | Sep 14, 1994 | Sep 14, 1994 | Costilla Petroleum Corporation | Crane | Gary-Glass 24 #1 | 4,500 | 10334279 |
| 427791 | Sep 6, 1994 | Sep 6, 1994 | Costilla Petroleum Corporation | Crockett | Noelke State 40 #1 | 7,500 | 10501249 |