Center for Biological Diversity

For Immediate Release, June 16, 2015

Contact: Noah Greenwald, (503) 484-7495,

Lawsuit Launched to Protect Rio Grande Cutthroat Trout Under Endangered Species Act

Trout Gone From 89 Percent of Historic Range,
But Denied Protection Under New Obama Administration Policy

DENVER, Colo.— The Center for Biological Diversity today filed a formal notice of intent to sue the U.S. Fish and Wildlife Service over its denial of Endangered Species Act protection to the highly imperiled Rio Grande cutthroat trout. In response to a 1998 petition and two lawsuits, the agency found in 2008 that the trout warranted protection due to habitat loss, introduction of nonnative trout, climate change and other factors, but September, 2014 reversed course and denied protection for the trout. 

“The Rio Grande cutthroat trout has already been wiped out from most of the streams where it once flourished and faces a multitude of ongoing threats,” said Noah Greenwald, endangered species director at the Center. “The Fish and Wildlife Service has for far too long denied this iconic trout the Endangered Species Act protection it desperately needs to survive.”

With deep crimson slashes on its throat — hence the name “cutthroat” — the Rio Grande cutthroat trout once swam a multitude of cool, clear streams in the Rio Grande, Pecos and Canadian River Basins from Colorado to southern New Mexico, but is now limited to a small number of tiny headwater streams in 11 percent of its historic range. In denying the trout protection, the Fish and Wildlife Service was able to largely ignore this extensive loss of historic range because of a recently adopted policy that reinterprets a key phrase in the Endangered Species Act. 

Under the Act a species qualifies for protection when it is “in danger of extinction in all or a significant of portion of its range.” The “significant portion of range” provision is vital because it requires federal wildlife agencies to protect species before they are at risk of going extinct globally.

The new policy, however, states that a species’ historic range will not be considered when determining if a species is endangered in a significant portion of its range, stopping species like the trout from receiving needed protections. In addition to challenging denial of protection for the trout, the groups put the agency on notice that they will also be challenging this policy. 

“Had this wrongheaded policy been in place in the 1970s, species like the bald eagle, gray wolf and grizzly bear would never have been protected in the lower 48 states simply because they still had healthy populations in Alaska and Canada,” said Greenwald. “In admitting that this beautiful trout is gone from 89 percent of its range and facing multiple threats but refusing to protect it anyway, the Obama administration is fundamentally undermining the Endangered Species Act.”

Most surviving Rio Grande cutthroat trout populations are too small and too isolated to be likely to survive, and many are hybridized with nonnative rainbow trout. Logging, road building, livestock grazing, pollution, hybridization and global warming are combining to push Rio Grande cutthroat toward extinction.

Read more about the Center’s work to save Rio Grande cutthroat trout.

The Center for Biological Diversity is a national, nonprofit conservation organization with more than 900,000 members and online activists dedicated to the protection of endangered species and wild places.

Go back