| O'Connor, Mary Ellen O-2-8485 | Mary Ellen Oconnor (FT-18 Sand) | Refugio | 1 | 12.7K | 31.8K | Apr 1996 – Jul 2026 |
| O'Connor, Mary Ellen O-2-8071 | Mary Ellen Oconnor (D-1) | Refugio | 1 | 0 | 0 | Jan 1995 – Jul 2026 |
| Obrien, J. J. G-2-225547 | Refugio Old | Refugio | 1 | 0 | 19.3K | Feb 2006 – Nov 2024 |
| O'Connor, L. W. G-2-147722 | Mary Ellen Oconnor (M-122) | Refugio | 1 | 0 | 46.3K | Nov 1993 – Jun 2014 |
| O'Connor, L. W. G-2-220622 | Mary Ellen Oconnor (H-105A) | Refugio | 1 | 0 | 69.5K | Feb 2006 – Jun 2014 |
| O'Connor, L. W. G-2-266114 | Mary Ellen Oconnor (D-1) | Refugio | 1 | 0 | 400 | Aug 2011 – Jun 2014 |
| O'Brien, J.J. G-2-202079 | Refugio Old (2960) | Refugio | 1 | 0 | 968 | May 2003 – Jun 2014 |
| O'Connor, Mary Ellen G-2-153797 | Mary Ellen Oconnor (D-1) | Refugio | 1 | 0 | 172K | Apr 1995 – May 2014 |
| O'Connor, Mary Ellen G-2-188888 | Mary Ellen Oconnor (H-117) | Refugio | 1 | 0 | 54.4K | Apr 2001 – May 2014 |
| O'Connor, Mary Ellen G-2-153585 | Mary Ellen Oconnor (D-1) | Refugio | 1 | 0 | 252K | Feb 1995 – May 2014 |
| O'Connor, Mary Ellen G-2-221305 | Mary Ellen Oconnor (4140) | Refugio | 1 | 0 | 60.5K | Jun 2006 – Apr 2014 |
| Oconnor, L. W. G-2-2977 | Mary Ellen Oconnor (D-1) | Refugio | 1 | 0 | 0 | Jan 1993 – Apr 2014 |
| O'Connor, Mary Ellen G-2-155077 | Mary Ellen Oconnor (H- 12) | Refugio | 1 | 0 | 146K | Jul 1995 – Mar 2014 |
| O'Connor, Mary Ellen G-2-147980 | Mary Ellen Oconnor (5500) | Refugio | 1 | 0 | 21.1K | Oct 1993 – Mar 2014 |
| O'Connor, Mary Ellen G-2-188886 | Mary Ellen Oconnor (FS-47 Sand) | Refugio | 1 | 0 | 4.15K | Apr 2001 – Mar 2014 |
| O'Connor, Mary Ellen G-2-150797 | Mary Ellen O'Connor (FS-20) | Refugio | 1 | 0 | 592K | Aug 1994 – Feb 2014 |
| Holmes G-3-66101 | Thursday (Woodbine) | — | 1 | 0 | 0 | Jan 1993 – Feb 2013 |
| O'Connor, Mary Ellen G-2-157778 | Mary Ellen Oconnor (H- 12) | Refugio | 1 | 0 | 219K | Dec 1995 – Jan 2013 |
| Guadalupe "B" de Garcia G-4-125582 | San Diego, N. (Yegua 5030) | Duval | 1 | 0 | 0 | Jan 1993 – Jun 2012 |
| O'Connor, L. W. G-2-142049 | Mary Ellen O'Connor (FS-20) | Refugio | 1 | 0 | 521K | Jan 1993 – Feb 2012 |
| O'Connor, L.W. G-2-156074 | Mary Ellen Oconnor (D-1) | Refugio | 1 | 0 | 95.2K | Nov 1995 – Sep 2011 |
| O'Connor, L.W. G-2-151036 | Mary Ellen Oconnor (H- 12) | Refugio | 1 | 0 | 80.8K | Aug 1994 – Aug 2011 |
| O'Connor, L. W. G-2-137359 | Mary Ellen Oconnor (FS-75) | Refugio | 1 | 0 | 67.2K | Jan 1993 – May 2011 |
| O'Brien, J. J. O-2-8664 | Refugio Old (5500) | Refugio | 2 | 8.91K | 2.68K | Apr 2001 – Apr 2011 |
| O'Connor, Mary Ellen O-2-8106 | Mary Ellen Oconnor (FQ-40 Sand) | Refugio | 2 | 1.23K | 6.7K | Sep 1995 – Mar 2008 |
| Oconnor, L. W. G-2-2999 | Mary Ellen Oconnor (FQ-25) | Refugio | 1 | 0 | 0 | Jan 1993 – Jun 2006 |
| O'Connor, Mary Ellen G-2-175425 | Mary Ellen Oconnor (D-1) | Refugio | 1 | 0 | 208K | Aug 1995 – May 2006 |
| O'Connor, Mary Ellen G-2-154157 | Mary Ellen Oconnor (D-1) | Refugio | 1 | 0 | 206K | Apr 1995 – May 2006 |
| O'Connor, Mary Ellen G-2-157107 | Mary Ellen Oconnor (D-1) | Refugio | 1 | 0 | 803 | Feb 1996 – May 2006 |
| Oconnor, Mary Ellen - Exxon G-2-164716 | Mary Ellen Oconnor (5000) | Refugio | 1 | 0 | 61.7K | Apr 1997 – May 2006 |
| O'Connor, L.W. G-2-190386 | Mary Ellen Oconnor (FS-75) | Refugio | 1 | 0 | 576K | Mar 2001 – Apr 2006 |
| O'Connor, L. W. G-2-183115 | Mary Ellen Oconnor (FS-1) | Refugio | 1 | 0 | 203K | Jan 2001 – Feb 2006 |
| O'Brien, J. J. G-2-185207 | Refugio Old | Refugio | 1 | 0 | 19.5K | Mar 2001 – Apr 2003 |
| O'Brien, J. J. O-2-8752 | Refugio Old | — | 0 | 0 | 0 | Sep 2002 – Sep 2002 |
| Oconnor, L. W. G-2-2985 | Mary Ellen Oconnor (H- 50) | Refugio | 1 | 0 | 0 | Jan 1993 – Jan 2001 |
| O'Connor, Thomas James O-2-8142 | Mary Ellen Oconnor (FS-96) | Bee | 2 | 100 | 25 | Feb 1996 – Feb 2000 |
| O'Connor, Mary Ellen G-2-150909 | Mary Ellen O'Connor (FS-20) | Refugio | 1 | 0 | 75.2K | Jan 1994 – Apr 1998 |