| 1 | DGHX | Searles Valley Minerals Operations | added 7/2007 | | NAKINA |
| 2 | DGHX | North American Chemical | added 10/2006; eliminated 7/2007 | | NAKINA |
| 3 | DGHX | IMC Chemicals | added 1/2002; 7/2005 | | NAKINA |
| 4 | DGHX | North American Chemical | added 7/1992; 1/1994-7/2000; eliminated 1/2002 | | NAKINA |
| 5 | DGHX | North American Chemical | added 7/92; 1/94-7/2000 | | NRHS |
| 6 | DGHX | *NORTH AMERICAN CHEMICAL CO. (IMC CHEMICALS) | | | PWRC |
| 7 | DGHX | +SEARLES VALLEY MINERALS OPERATIONS, INC. | | | PWRC |
| 8 | DGHX | North American Chemical | | | RSRV |
| 9 | DGHX | SEARLES VALLEY MINERALS OPERATIONS | | | SCAC4 |
