February 16, 1998 – The Center petitioned the U.S. Fish and Wildlife Service to list the Rio Grande cutthroat trout as an endangered species.
June 5, 1998 – The Center and Sky Island Watch simultaneously announced a campaign to end all livestock grazing along streams in the Gila Headwaters/Sky Island bioregion and throughout the Southwest.
June 9, 1999 – The Center, with the help of several other conservation groups, filed a lawsuit to force the U.S. Fish and Wildlife Service to consider listing the Rio Grande cutthroat trout as an endangered species after the agency announced that it planned to rely only on existing conservation efforts.
November 5, 2001 – The Center, Pacific Rivers Council and Trout Unlimited launched a western native trout campaign to protect and restore all native trout species in the western United States. One of the campaign's first steps was to release a scientific report on the importance of roadless areas to imperiled trout species.
March 20, 2002 – The Center reached a legal settlement with the Service, where the agency committed to completing a status review of the species and issuing a listing decision within a few months. The agency determined that listing the Rio Grande cutthroat trout as a protected species was not warranted because the fish was unlikely to become endangered.
February 25, 2003 – The Center, in coalition with the Biodiversity Conservation Alliance and others, filed suit against the Service to overturn its decision not to list the Rio Grande cutthroat trout as an endangered species.
May 14, 2008 – The Service completed its status review of the Rio Grande cutthroat trout, announcing that protection of the species is warranted. The agency chose not to act, instead adding the fish to a list of candidate species with no real protections.
July 12, 2011 – The Center reached a landmark agreement with the Fish and Wildlife Service compelling the agency to move forward in the protection process for 757 species, including the Rio Grande cutthroat trout.