On February 5, 2008, the U.S. Fish and Wildlife Service (FWS) issued a 12-month finding regarding the petition to list the Gunnison's prairie dog (Cynomys gunnisoni) as a threatened or endangered species. In its determination, the FWS found that the species was not endangered or threatened throughout all of its range. It also found, however, that the portion of the current range of the species in central and south-central Colorado and north-central New Mexico represents a significant portion of the range where the species warrants listing, but that listing is precluded by higher priority actions. Thus, the FWS found that listing is not warranted in the "prairie" range of the species and is warranted but precluded in the "montane" portion of its range.
On March 24, 2009, WildEarth Guardians filed suit challenging FWS's listing determination. Specifically, WildEarth Guardians challenged the FWS's decision to limit listing to only the montane portion of the Gunnison's prairie dog's range and the FWS's "warranted but precluded" finding with respect to the montane portion of the species' range. As in other cases, the FWS relied heavily upon a 2007 Solicitor's Opinion that authorizes the FWS to list a species in only that portion of its range in which protections are necessary.
On October 9, 2009, MSLF filed its motion to intervene on behalf of the Arizona Cattle Growers' Association and New Mexico Cattle Growers' Association. That motion was denied on November 25, 2009. On November 25, 2009, the district court granted the Cattle Growers' Associations permission to file an amicus brief. The Cattle Growers Associations filed their amicus brief on December 16, 2009, and briefing on cross-motions for summary judgment was completed.
On December 16, 2009, the federal defendants filed their opposition to WildEarth Guardians' motion and their cross-motion for summary judgment. On September 8, 2010, the federal defendants filed a motion to stay the proceedings until October 14, 2010, following the ruling by the Montana federal district court in Defenders of Wildlife that the Solicitor's Opinion regarding distinct population segments is contrary to the plain language of the ESA and thus unlawful. On September 30, 2010, the district court denied the motion for stay and granted WildEarth Guardians' motion for summary judgment, set aside the government's Gunnison's prairie dog finding, and remanded the matter to the agency. Meanwhile, on March 1, 2011, the district court approved a stipulation under which the federal defendants agreed to pay WildEarth Guardians $47,530 in attorney fees. On November 19, 2010, the FWS filed a notice of appeal. On March 4, 2011, the new Solicitor withdrew the Solicitor's Opinion upon which the challenged listing determination was based.