| 1 | UOEX | Union Oil Co. of California | added 10/1984; eliminated 1/1987 | | NAKINA |
| 2 | UOEX | UNOCAL | added 1/1987; eliminated 7/1992 | | NAKINA |
| 3 | UOEX | UNO-VEN | added 7/1992; 1/1994; eliminated 4/1998; 7/2000-7/2005 (not listed) | | NAKINA |
| 4 | UOEX | Union Oil Co. of California | added 10/84; eliminated 1/87 | | NRHS |
| 5 | UOEX | UNOCAL | added 1/87; eliminated 7/92 | | NRHS |
| 6 | UOEX | UNO-VEN | added 7/92; 1/94; eliminated 4/98; 7/2000 | | NRHS |
| 7 | UOEX | UNO-VEN [UNOCAL; UNION OIL CO. OF CALIFORNIA] | | | PWRC |
| 8 | UOEX | UNO-VEN | | | RSRV |
| 9 | UOEX | UNO-VEN | | | SCAC4 |
