The Endangered Species Act of 1973 directs the USFWS to identify and protect rare plants and animals. The following categories are currently used to rank listed and candidate species. The candidate system was revised in 1996, eliminating the old category of C2.
| Designation | Description |
|---|---|
| LE | Listed Endangered. In danger of extinction. For plants this applies to all of a taxon's range; for animals this may apply to only a portion of a taxon's range |
| LT | Listed Threatened. Likely to become Endangered in the near future. For plants this applies to all of a taxon's range; for animals this may apply to only a portion of a taxon's range |
| LEXN | Listed Endangered - Nonessential Experimental Population. Some populations in the state are Endangered and under the full protection of the Endangered Species Act; others are Endangered but receive lower levels of protection due to their reintroduced, temporary, or otherwise provisional condition |
| WPE | Warranted, Proposed for listing as Endangered |
| WPT | Warranted, Proposed for listing as Threatened |
| C | Candidate; Warranted but Precluded. Existing biological information supports a formal proposal to list as Endangered or Threatened, but developing a listing regulation is precluded by higher priority listing activities. |
| PDL | Proposed for delisting from existing status. |
| UR | Petition Under Review. A petition to list as Endangered or Threatened has been received by USFWS and is awaiting USFWS review |
| DM | Delisted from Endangered or Threatened status and formally monitored. |
| NW | Not Warranted for Listing. A formal proposal for listing as Endangered or Threatened was recently denied |
USFS has adopted policies to ensure that agency actions do not drive rare taxa towards listing as Threatened or Endangered under the Endangered Species Act.
USFS Region 2 and Region 4 have developed lists of "Sensitive Species" that warrant special attention on USFS lands (USDA FS 1991, 1994, 2003). Sensitive species are defined as "plant and animal species identified by the Regional Forester for which population viability is a concern as evidenced by: (a) significant current or predicted downward trends in population numbers or density, and/or (b) significant current or predicted downward trends in habitat capability that would reduce a species' existing distribution." The following codes are used to represent regional sensitive species designations by USFS:
| Designation | Description |
|---|---|
| USFS-R2 | Sensitive in Region 2 - Region 2 National Forests in Wyoming: Bighorn, Black Hills, Medicine Bow, and Shoshone National Forests, and Thunder Basin National Grassland |
| USFS-R4 | Sensitive in Region 4 - Region 4 National Forests in Wyoming: Bridger-Teton, Caribou, Targhee, Wasatch-Cache, and Ashley (including Flaming Gorge National Recreation Area) National Forests |
In addition to regional lists of "Sensitive" species, some individual National Forests also maintain a list of Species of Local Concern (SOLC). The codes used by WYNDD for such SOLC designations indicate the National Forest or National Grassland for which they are in effect:
| Code | Description |
|---|---|
| BgHrnNF | Bighorn National Forest |
| BlkHlNF | Black Hills National Forest |
| BTNF | Bridger-Teton National Forest |
| CTNF | Caribou-Targhee National Forest |
| MBNF | Medicine Bow National Forest |
| SNF | Shoshone National Forest |
| TBNG | Thunder Basin National Grassland |
BLM has adopted policies to ensure that agency actions do not drive rare taxa towards listing as Threatened or Endangered under the Endangered Species Act.
The BLM Wyoming State Office has established a list of "Sensitive" Species warranting special attention on BLM lands (USDI BLM 2001, 2002, 2010). BLM Sensitive species are "species that could easily become endangered or extinct in the state", including (a) species under status review by the FWS/ National Marine and Fisheries Service, (b) species whose numbers are declining so rapidly that Federal listing may become necessary, (c) species with typically small or fragmented populations, and (d) species inhabiting specialized refugia or other unique habitats. The following codes are used to represent sensitive species designations by BLM:
| Designation | Description |
|---|---|
| Sensitive | On Sensitive Species List in Wyoming (no invertebrate animal species are listed) |
