Suit Filed to Protect Yellowstone Cutthroat Trout

US Fish and Wildlife Service failed to use best available science


Mike Harris, Earthjustice, 303-623-9466


Noah Greenwald, Center for Biological Diversity, 503-484-7495.


Chris Frissell, Pacific Rivers Council, 406-883-1503 or 406-883-3891

Earthjustice filed suit against the U.S. Fish and Wildlife Service for illegally denying listing of the Yellowstone cutthroat trout as a threatened or endangered species under the Endangered Species Act. In February 2001 the Fish and Wildlife Service turned down a request to protect the trout. That request was filed by a coalition of groups including The Center for Biological Diversity, Biodiversity Conservation Alliance, Ecology Center and Pacific Rivers Council.

“The FWS failed to even look at the ample scientific data in the petition demonstrating that the Yellowstone cutthroat trout has been disappeared entirely in nearly 60 percent of its historic range, and that the species is in real peril in those areas where it has so far managed to hang on,” said Mike Harris, an attorney for Earthjustice, who is representing the groups. “This is yet another case of the Bush administration ignoring the science and its legal obligations under the ESA. As a result, Americans face the loss of a famed species like the Yellowstone cutthroat trout.”

Yellowstone cutthroat were once widely distributed throughout the Yellowstone River from its headwaters to the Tongue River, and the Snake River above Shoshone Falls, including portions of southern Montana, northwestern Wyoming, southeastern Idaho, and northern Nevada and Utah. They have been eliminated from most of this historic range by a combination of habitat degradation and replacement by non-native trout. Fish and Wildlife’s finding, for example, concedes that pure Yellowstone cutthroat have been reduced to 10% of their historic range in Montana.

“The Fish and Wildlife Service’s finding utterly failed to consider the magnitude of threat facing the Yellowstone cutthroat trout,” states Noah Greenwald, conservation biologist with the Center for Biological Diversity. “The Yellowstone cutthroat trout is beset by a multitude of threats, including non-native trout, habitat degradation, population fragmentation, and disease, and requires immediate protection under the Endangered Species Act. The Yellowstone cutthroat trout has been reduced to a fraction of its former range and continues to decline. Such decline clearly indicates the trout merits listing as endangered and that Fish and Wildlife’s finding is both illogical and illegal.”

Threats to the Yellowstone cutthroat trout are mounting even in the heart of its diminished range. In 1994, lake trout, a voracious, nonnative predator of cutthroat trout, were discovered in Yellowstone Lake, home of the largest remnant populations of Yellowstone cutthroat. And in 2003, whirling disease, an exotic trout parasite, was found to have decimated Yellowstone cutthroat trout in Pelican Creek, the principal spawning tributary of Yellowstone Lake that supported as many as 30,000 fish in the 1980s.

“No known management measures can completely stop the spread of the principle threats, including disease, displacement by lake and brook trout, and hybridization with nonnative rainbow trout,” said Dr. Chris Frissell, Senior Staff Scientist for the Pacific Rivers Council. “But we do know that each of these threats is exacerbated by habitat degradation from livestock grazing, mining, logging, roadbuilding, dams, and flow diversion. Protecting and restoring the last, best habitats of Yellowstone cutthroat trout, many of which remain without strict protection today, is absolutely critical for their future survival and recovery.”

Yellowstone cutthroat trout are the nation’s first identified cutthroat trout. In 1884, Yellowstone cutthroat trout from Rosebud Creek, a southern Montana tributary to the Yellowstone River, were the first of now 14 recognized subspecies to be described as “cutthroat trout” because of their characteristic orange to crimson slashes underneath the jaw. In a story now common through much of their historic range, Yellowstone cutthroat trout in Rosebud Creek were long ago lost to habitat deterioration and displacement by introduced brook, brown and rainbow trout.

Additional Resources

About Earthjustice

Earthjustice is the premier nonprofit environmental law organization. We wield the power of law and the strength of partnership to protect people's health, to preserve magnificent places and wildlife, to advance clean energy, and to combat climate change. We are here because the earth needs a good lawyer.