August 24, 2010 – The Center petitioned the U.S. Fish and Wildlife Service to list the white-tailed ptarmigan in the lower 48 states as threatened under the Endangered Species Act, primarily due to the threat of global warming.
July 12, 2011 – The Center reached a landmark agreement with the Service that mandated protection decisions for 757 species, including the white-tailed ptarmigan.
June 4, 2012 – In response to our petition and as a result of our 757-species agreement, the U.S. Fish and Wildlife Service found that the Mt. Rainier and southern subspecies of white-tailed ptarmigans may warrant protection under the Endangered Species Act and initiated a status review.