Office of External Affairs
Mountain-Prairie Region


U.S. Fish and Wildlife Service
Mountain-Prairie Region
134 Union Boulevard
Lakewood, Colorado 80228

December 15, 2010

Contacts:  Ellen Mayo (970) 243-2778 ext. 14

                 Diane Katzenberger 303-236-4578   




The U.S. Fish and Wildlife Service announced today that it has determined that skiff milkvetch (Astragalus microcymbus) and Schmoll’s milkvetch (Astragalus schmolliae) warrant protection under the Endangered Species Act, but that listing the species under the Act is precluded by the need to take other listing actions of a higher priority.

The Service will add skiff milkvetch and Schmoll’s milkvetch to its list of candidate species and review their status annually. When a "warranted but precluded" finding is made for a species, it becomes a candidate for listing. If we propose to list skiff milkvetch or Schmoll’s milkvetch in the future, the public will have an opportunity to comment.

We made the determination in response to a petition to list 206 species in the Mountain-Prairie Region filed July 30, 2007, by the Forest Guardians (now WildEarth Guardians).  We completed an initial review – known as a 90-day finding - on August 18, 2009 and concluded that the petition contained substantial information supporting further study of the status of skiff milkvetch and Schmoll’s milkvetch.  We have completed a comprehensive review – known as a 12-month finding – and determined that there is sufficient scientific and commercial data to propose listing the species as endangered or threatened throughout their respective ranges.  However, we are precluded from beginning work immediately on a listing proposal because our limited resources must be devoted to other higher-priority actions

Both of these species have restricted ranges.  Skiff milkvetch is known largely from a 20-square mile area just southwest of Gunnison, Colorado, and Schmoll’s milkvetch is known from about 4,000 acres in Mesa Verde National Park and the Ute Mountain Ute Tribal Park.  Both species are herbaceous forbs in the pea family that live for several years, retreating underground during the winter months.  Otherwise, the two species are quite different.  They are separated by over 100 miles, are not closely related within the Astragalus genus, and have very different habitat requirements.  Skiff milkvetch is found on sparsely vegetated slopes within open sagebrush habitat, and Schmoll’s milkvetch is found within pinyon-juniper forests on mesa tops.


The primary threats to skiff milkvetch are habitat fragmentation and degradation, increasing recreational use (primarily from roads and trails within the Hartman Rocks Recreation Area), and the inadequacy of existing regulatory mechanisms on private and Federal lands.  Survey and monitoring data suggests the species is in decline.


The primary threats to Schmoll’s milkvetch are modification of its habitat due to the invasion of non-native cheatgrass following wildfires, prescribed fires, and fire break clearings.  Cheatgrass is highly flammable and increases fire frequency.  Frequent fires are likely to prevent recovery of the species’ pinyon-juniper habitat.  There are no landscape-scale methods known to be effective in controlling cheatgrass.  Drought due to the warmer and drier climate trend in the Southwestern United States is a significant contributor to degradation of the habitat for this species.


A copy of the finding and other information about skiff milkvetch and Schmoll’s milkvetch are available on the Internet at at Docket Number FWS-R6-ES-2010-0080, or by contacting Al Pfister at the Western Colorado Ecological Services Office at 970–243–2778.  The public is encouraged to continue to provide information to the Service regarding the status of the skiff milkvetch and Schmoll’s milkvetch.  Information can be provided to the Western Colorado Field Office 764 Horizon Drive, Building B, Grand Junction, Colorado 81506-3946


The mission of the U.S. Fish and Wildlife Service is working with others to conserve, protect and enhance fish, wildlife, plants and their habitats for the continuing benefit of the American people.  We are both a leader and trusted partner in fish and wildlife conservation, known for our scientific excellence, stewardship of lands and natural resources, dedicated professionals and commitment to public service.  For more information on our work and the people who make it happen, visit