Office of External Affairs
Mountain-Prairie Region


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

August 17, 2007                                                   

Contacts:  Chuck Davis 303-236-4253

                 Barb Perkins 303-236-4588


Yellowstone National Park Bison Do Not Meet Criteria for Listing Under the ESA

Management Plan Now Provides Substantial Protection for Herd


The U. S. Fish and Wildlife Service has concluded that a petition to list the Yellowstone National Park (YNP) bison herd as threatened or endangered under the Endangered Species Act (ESA) does not provide substantial scientific or commercial information to indicate listing may be warranted at this time. 


The Service received the petition to list the YNP bison herd and to designate critical habitat in and adjacent to YNP from an individual, Mr. James Horsley of Moorhead, Minnesota on February 11, 1999.  Action on this petition has been precluded until now because of higher listing priorities.  This finding does not consider the aspect of critical habitat because it is not a petitionable action under the ESA.


The Service finds that the YNP bison herd is not in danger of going extinct. Since the petition was filed, a multi-agency Joint Bison Management Plan was finalized in 2000. The plan provides substantial protection for the YNP bison herd and therefore there is not a current credible threat to the herd’s existence, which would be necessary to list the herd under the ESA.


The listing petition identified as a cause for listing the 1996-1997 winter when brucellosis control effort that resulted in the death of some bison that ranged outside the park. However, since then the implementation of the management plan provides a method of addressing brucellosis without jeopardizing the Yellowstone herd’s continued existence.


The petitioner asked the Service to consider designating the YNP bison herd as a distinct population segment (DPS).  A distinct population segment of a vertebrate species can be treated as a species for purposes of listing if that population segment satisfies specific standards set by the Service’s regulations. The standards require it to be discrete from the remainder of the population and significant to the species to which it belongs.  Once those two standards are met, the Service conducts status and threats analyses.


The YNP bison herd is considered discrete because it is the only herd in the lower 48 States that has remained in a wild state since prehistoric times.  All bison herds in the United States are reconstituted herds and most are confined with fencing or otherwise range restricted. 


In addition to reviewing the petition, the Service examined information that was contained in its files or readily available.


For more information, refer to the published finding in the Federal Register, dated August 15, 2007,


The U.S. Fish and Wildlife Service is the principal Federal agency responsible for conserving, protecting and enhancing fish, wildlife and plants and their habitats for the continuing benefit of the American people. The Service manages the 95-million-acre National Wildlife Refuge System, which encompasses 545 national wildlife refuges, thousands of small wetlands and other special management areas. It also operates 69 national fish hatcheries, 64 fishery resources offices and 81 ecological services field stations. The agency enforces federal wildlife laws, administers the Endangered Species Act, manages migratory bird populations, restores nationally significant fisheries, conserves and restores wildlife habitat such as wetlands, and helps foreign and Native American tribal governments with their conservation efforts. It also oversees the Federal Assistance program, which distributes hundreds of millions of dollars in excise taxes on fishing and hunting equipment to state fish and wildlife agencies.

  - FWS -