| Clay, H. R. O-10-2741 | Endeavor Energy Resources L.P. only | Howard Glasscock | Howard | 25 | 879K | 68.8K | Jan 1993 – Nov 2011 |
| Clay O-10-2750 | Cimarex Energy Co. of Colorado only | Howard Glasscock | Howard | 37 | 865K | 415K | Jan 1993 – Nov 2011 |
| Barclays B Unit O-10-50687 | Apache Corporation only | Spraberry (Trend Area) | Howard | 2 | 597K | 1.2M | Jun 2018 – Apr 2026 |
| Barclays Unit O-10-49389 | Apache Corporation only | Spraberry (Trend Area) | Howard | 2 | 532K | 1.04M | Aug 2017 – Apr 2026 |
| Clay, H. R. -E- O-10-2692 | Quantum Resources Management,llc only | Howard Glasscock | Howard | 48 | 526K | 4.73K | Jan 1993 – Nov 2011 |
| Clay, H. R. -E- O-10-18993 | Quantum Resources Management,llc only | Howard-Glasscock (Glorieta) | Howard | 24 | 267K | 2.36K | Jan 1993 – Nov 2011 |
| Clay O-10-42235 | Grayrock Energy II, LLC only | Howard Glasscock (Consolidated) | Howard | 29 | 230K | 24.9K | Dec 2011 – Apr 2026 |
| Clay, H. R. -A- O-10-2691 | Quantum Resources Management,llc only | Howard Glasscock | Howard | 42 | 205K | 12.3K | Jan 1993 – Nov 2011 |
| Clay, H. R. -C- O-10-2823 | Breitburn Operating L.P. only | Howard Glasscock | Howard | 10 | 191K | 6.97K | Jan 1993 – Nov 2011 |
| Clay, H. R. O-10-2738 | Wash, Robert C. Inc. only | Howard Glasscock | Glasscock | 27 | 186K | 45 | Jan 1993 – Nov 2011 |
| Clay, H. R. -A- O-10-18992 | Quantum Resources Management,llc only | Howard-Glasscock (Glorieta) | Howard | 11 | 143K | 5.33K | Jan 1993 – Nov 2011 |
| Clay, H. R. -B- Amoco O-10-2822 | Quantum Resources Management,llc only | Howard Glasscock | Howard | 10 | 137K | 3.84K | Jan 1993 – Nov 2011 |
| Clay, H. R. -A- O-10-8680 | Wash, Robert C. Inc. only | Howard Glasscock | Howard | 21 | 135K | 118 | Jan 1993 – Nov 2011 |
| Clay, H. R. O-10-41676 | Grayrock Energy II, LLC only | Howard Glasscock (Consolidated) | Howard | 36 | 135K | 0 | Dec 2011 – Apr 2026 |
| Clay, H. R. -A- O-10-2744 | Robertson Resources, Inc. only | Howard Glasscock | Howard | 6 | 127K | 55.9K | Jan 1993 – Oct 2014 |
| Clay, H. R.-E- O-10-41290 | Landmark IP, LLC only | Howard Glasscock (Consolidated) | Howard | 59 | 116K | 0 | Dec 2011 – Dec 2025 |
| Clay, H. R. O-10-47933 | Wash, Robert C. Inc. only | Howard Glasscock (Consolidated) | Glasscock | 20 | 111K | 121 | Dec 2011 – Apr 2026 |
| Clay, H. R.-A- O-10-41289 | Landmark IP, LLC only | Howard Glasscock (Consolidated) | Howard | 36 | 86.1K | 0 | Dec 2011 – Dec 2025 |
| Clay, H. R. -B- O-10-18999 | Quantum Resources Management,llc only | Howard-Glasscock (Glorieta) | Howard | 10 | 59.4K | 2.83K | Jan 1993 – Nov 2011 |
| Clay, H. R. -G- O-10-2694 | Quantum Resources Management,llc only | Howard Glasscock | Howard | 5 | 54.3K | 2.75K | Jan 1993 – Nov 2011 |
| Clay, H. R. -B- O-10-2745 | Robertson Resources, Inc. only | Howard Glasscock | Howard | 4 | 51.4K | 27 | Jan 1993 – Oct 2014 |
| Clay, H.R.-McNalen O-10-2777 | Quantum Resources Management,llc only | Howard Glasscock | Howard | 19 | 50.8K | 594 | Jan 1993 – Nov 2011 |
| Clay, H. R. O-10-2682 | O'Ryan Oil and Gas only | Howard Glasscock | Howard | 12 | 44.8K | 84 | Jan 1993 – Nov 2011 |
| Clay, H. R. O-10-2690 | Breitburn Operating L.P. only | Howard Glasscock | Howard | 23 | 41.3K | 4.74K | Jan 1993 – Nov 2011 |
| Clay, H. R. -A- O-10-48144 | Wash, Robert C. Inc. only | Howard Glasscock (Consolidated) | Howard | 17 | 38.3K | 121 | Dec 2011 – Apr 2026 |
| Clay,h. R., -B- O-10-2778 | O'Ryan Oil and Gas only | Howard Glasscock | Howard | 13 | 37.5K | 83 | Jan 1993 – Nov 2011 |
| Clay, H. R. -C- O-10-25450 | Quantum Resources Management,llc only | Howard-Glasscock (Glorieta) | Howard | 1 | 35.9K | 944 | Jan 1993 – Nov 2011 |
| Clay, H. R. O-10-2746 | Vision Natural Resources, LP only | Howard Glasscock | Howard | 6 | 34.6K | 16 | Jan 1993 – Oct 2014 |
| Clay, H. R. O-10-13460 | Wash, Robert C. Inc. only | Howard Glasscock | Howard | 12 | 25.8K | 118 | Jan 1993 – Nov 2011 |
| Clay, H. R. -A- O-10-48046 | Robertson Resources, Inc. only | Howard Glasscock (Consolidated) | Howard | 5 | 23.2K | 0 | Nov 2014 – Mar 2026 |
| Clay, H. R. -B- O-10-48047 | Robertson Resources, Inc. only | Howard Glasscock (Consolidated) | Howard | 4 | 19.5K | 0 | Nov 2014 – Mar 2026 |
| Clay, H. R. -C- O-10-12702 | Legacy Reserves Operating LP only | Howard Glasscock | Howard | 4 | 17.6K | 187 | Jan 1993 – Nov 2011 |
| Clay, H. R., -A- O-10-20755 | O'Ryan Oil and Gas only | Howard-Glasscock (Glorieta) | Howard | 1 | 17.1K | 83 | Jan 1993 – Nov 2011 |
| Clay, H. R. -B- O-10-48175 | Wash, Robert C. Inc. only | Howard Glasscock (Consolidated) | Howard | 8 | 16.6K | 121 | Dec 2011 – Apr 2026 |
| Clay, H. R., -B- O-10-18998 | O'Ryan Oil and Gas only | Howard-Glasscock (Glorieta) | Howard | 1 | 14.9K | 84 | Jan 1993 – Nov 2011 |
| Clay, H. R.-McNallen O-10-41299 | Landmark IP, LLC only | Howard Glasscock (Consolidated) | Howard | 11 | 12.6K | 0 | Dec 2011 – Apr 2022 |
| Clay, H.R.-G- O-10-41291 | Landmark IP, LLC only | Howard Glasscock (Consolidated) | Howard | 4 | 11.5K | 0 | Dec 2011 – Jun 2016 |
| Clay, H. R. East O-10-48010 | Wash, Robert C. Inc. only | Howard Glasscock (Consolidated) | Howard | 3 | 10K | 1 | Nov 2014 – Apr 2026 |
| Clay, H. R. O-10-24284 | Quantum Resources Management,llc only | Howard-Glasscock (Glorieta) | Howard | 2 | 8.84K | 79 | Jan 1993 – Jan 2005 |
| Clay, H. R. -C- O-10-41666 | Wash, Robert C. Inc. only | Howard Glasscock (Consolidated) | Howard | 4 | 8.62K | 67 | Dec 2011 – Apr 2026 |
| McNallen, H. R. Clay O-10-36595 | Quantum Resources Management,llc only | Howard-Glasscock (Glorieta) | Howard | 3 | 6.64K | 0 | Jan 2001 – Jan 2005 |
| Clay. H.R.-B-Amoco O-10-41293 | Landmark IP, LLC only | Howard Glasscock (Consolidated) | Howard | 5 | 3.47K | 0 | Dec 2011 – Sep 2014 |
| Clay, H. R. -C- O-10-41300 | Landmark IP, LLC only | Howard Glasscock (Consolidated) | Howard | 10 | 3.33K | 0 | Dec 2011 – Jun 2013 |
| Clay, H. R.-B- O-10-41303 | Landmark IP, LLC only | Howard Glasscock (Consolidated) | Howard | 10 | 2.93K | 0 | Dec 2011 – Mar 2020 |
| Clay, H. R., -B- O-10-41029 | O'Ryan Oil and Gas only | Howard Glasscock (Consolidated) | Howard | 13 | 1.78K | 0 | Dec 2011 – Mar 2026 |
| Clay, H. R. O-10-41030 | O'Ryan Oil and Gas only | Howard Glasscock (Consolidated) | Howard | 11 | 1.71K | 0 | Jan 2012 – Mar 2026 |
| Clay, H. R., -A- O-10-41031 | O'Ryan Oil and Gas only | Howard Glasscock (Consolidated) | Howard | 1 | 1.41K | 0 | Jan 2012 – Mar 2026 |
| Clay, H. R. -H- O-10-12031 | Ica Energy Operating, L.L.C. only | Howard Glasscock | Howard | 2 | 881 | 26 | Jan 1993 – Nov 1998 |
| Clay, H.R. O-10-41288 | Landmark IP, LLC only | Howard Glasscock (Consolidated) | Howard | 14 | 704 | 0 | Dec 2011 – Jul 2021 |
| Clay, H. R. -A- O-10-41302 | Quantum Resources Management,llc only | Howard Glasscock (Consolidated) | Howard | 9 | 0 | 0 | — |