Center for Biological Diversity

Protecting endangered species and wild places of western North America
and the Pacific through science, policy, education, and environmental law.


Scientific report: roadless areas provide last refuge for native trout in the West

Kieran Suckling, Center for Biological Diversity (Arizona): 520-623-5252 x304
David Bayles, Pacific Rivers Council (Oregon): 541-345-0119
Jeff Kessler, Biodiversity Associates (Wyoming): 307-742-7978
Chris Frissell, Pacific Rivers Council (Montana): 406-883-1503

(TUCSON, ARIZ./ EUGENE, ORE./LARAMIE, WY) – A scientific computer mapping analysis released by the Western Native Trout Campaign today demonstrates that native trout species in the western United States are strongly correlated with the region’s remaining roadless areas. If the federal roadless policy adopted in 2000 is withdrawn, many populations of native trout will likely become extinct.

The report, Imperiled Western Trout and the Importance of Roadless Areas, used sophisticated geographic information systems to map out the locations of eight native trout species and federal roadless areas. It found a very strong correlation between “strong” fish populations and roadless areas: Gila trout (99%), greenback cutthroat trout (75%), bull trout (76%), westslope cutthroat trout (71%), Colorado River cutthroat trout (62%), Rio Grande cutthroat trout (39%), Bonneville cutthroat trout (32%) and redband trout (17%).

Despite their ecological importance, at least 2.8 million acres of inventoried roadless areas on U.S. Forest Service lands have been lost to road construction over the last 20 years. Millions more have been lost on BLM lands and in smaller, uninventoried roadless tracts. Another 34.3 million acres of inventoried roadless areas on public lands are vulnerable to road construction under existing regulations.

“This report shows us that roadless areas provide a refuge for the strongest surviving populations of native trout,” says David Bayles, conservation director for Pacific Rivers Council. “These refuges are sacred ground for native trout. We must defend them from oil and gas drilling, logging, mining, grazing, road building or anything else that would harm these last best places.”

“Native trout and wilderness are nearly synonymous,” said Kieran Suckling, Executive Director of the Center for Biological Diversity, “you can’t have one without the other. It is imperative that we not build more roads into America’s last remaining wild places, too many trout populations are already extinct.”

The recently formed Western Native Trout Campaign ( is a coalition of conservation and angling organizations dedicated to conducting scientific studies and public education about native trout and their habitats. Members include the Center for Biological Diversity (Tucson, AZ), Pacific Rivers Council (Eugene, OR), and Biodiversity Associates (Laramie, WY).

Today’s report is the first of many research projects the Trout Campaign will address in coming years. It is the most comprehensive and examination to date of the status of eight native trout species and their association with roadless areas. These species range throughout the Rocky Mountain West from Oregon to Arizona, Nevada to Montana. The report has two primary findings:

One: Stronger populations of native trout are now found in a only a tiny fraction of their historic ranges. Using computerized spatial analysis, the report found that stronger populations of seven of the eight species analyzed now occupy less than 6% of their historic range and three species now occupy less than 1% of their historic range. (“Stronger” populations refers to those areas where native trout are most abundant or most genetically pure.) Two species outside of the analysis, the Alvord cutthroat and yellowfin cutthroat, are already extinct. Roads and associated activities are a major cause of habitat degradation that has triggered these declines.

Two: Most stronger remaining native trout populations are found in roadless areas with the stronger populations of some species almost exclusively limited to roadless areas.

Together, these findings indicate that the protection of roadless areas is essential to the continued existence of native trout.

Chris Frissell, Ph.D., Aquatic Ecologist with Pacific Rivers Council, says, “Management plans that fail to preserve these key roadless lands place native trout in jeopardy. Scientific studies have shown that roads pose many serious threats to native trout, but this report is the first hard look at the sweeping scale at which roadless areas are important across the West.”

“It’s time to stop ignoring the science in our public policy decisions regarding both roadless areas and native trout. Native trout and roadless areas are irreplaceable parts of our natural heritage that need complete protection,” said Jeff Kessler, Conservation Director of Biodiversity Associates.

Jon Rhodes, Aquatic Scientist with the Center for Biological Diversity says, “Our report is the most comprehensive assessment of its kind. It shows that roadless area protection is vital, if people are to see or catch native trout in the future.” Rhodes also states, “ This report explodes the myth that native trout flourish in watersheds degraded by roads.”

In July 2001, the Bush administration re-opened the rule-making process on the Forest Service’s Roadless Area Conservation Rule, which had closed 58 million acres of inventoried roadless areas to road building. During the public comment period for the original rule, the Forest Service received an estimated 2 million comments — the most of any federal project in U.S. history. The vast majority of these comments supported increased roadless area protection.

The Western Native Trout Campaign recommends that the previous roadless policy be expanded to protect all roadless areas greater than 1,000 acres, as recommended by aquatic scientists since 1994. The previous roadless rule protected only areas greater than 5,000 acres, which is inadequate to protect trout.

The Western Native Trout Campaign report also concludes that protecting existing roadless habitat from harmful practices like roads, logging and grazing is far more effective, biologically and economically, than attempts to restore habitat after it has been damaged.

“The bottom line is that if we don’t protect roadless areas, we will continue to lose trout populations in the last strongholds of the West,” said David Bayles of the Pacific Rivers Council.

The complete report and maps are available online at:


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