Bringing The Montana Grayling Back From Brink of Extinction

River-dwelling relatives of trout and salmon, Arctic graylings now inhabit less than 5% of their historic range, with a last refuge in one short stretch of the Big Hole River.


Regional Office / Program

Case Overview

A member of the salmon family, the Arctic grayling is a beautiful fish with a prominent dorsal fin. The species thrives in cold freshwater streams and rivers across Canada and Alaska. Historically, fluvial populations of Arctic grayling existed in only two places in the lower-48 states: Michigan and the upper Missouri River of Montana. Populations in Michigan went extinct by the 1930s, and populations in Montana were restricted to the Big Hole River and a few lakes by the end of the 1970s. Studies demonstrate that Montana grayling are genetically distinct from populations in Canada and Alaska.

A candidate for protection since 1982, the grayling was first petitioned for listing in 1991 by the Biodiversity Conservation Alliance, now part of the Center for Biological Diversity, and George Wuerthner, leading to the Fish and Wildlife Service’s first finding that the grayling warranted endangered status in 1994. Rather than providing that protection, however, the agency put the fish on a candidate list, where it received no protection.

The grayling subsequently experienced severe declines in response to the near drying-up of the Big Hole River on an annual basis caused by increased irrigation use and drought. Fearing the extinction of the fish, the Center, Western Watersheds Project and Wuerthner sued for protection in 2003. In 2005, the Fish and Wildlife Service agreed to issue a new decision on listing, but rather than list the species, the agency reversed course and denied it protection, arguing that extinction of the Montana population would be insignificant. The groups again sued, and in 2010 the Fish and Wildlife Service once again reversed course, concluding that the grayling warranted protection, but again only added it to a candidate list. In 2011, the Center reached a settlement agreement requiring the agency to either move forward with protection or withdraw such protection by the end of fiscal year 2014.

In August 2014, the agency reversed course, withholding protection from the rare and beautiful relative of trout and salmon. In denying the grayling protection, the agency argued that voluntary efforts by private landowners and the state of Montana, guided by a conservation agreement in place since 2006, have alleviated threats to the fish’s survival. Although many individual projects to improve habitat have been completed under the agreement, the grayling continues to face numerous threats, including excessive water withdrawals for irrigation, non-native trout and ongoing habitat degradation.

A primary factor in the decline of the species’ range has been the ongoing diversion of water from the fish’s stream habitat for agricultural uses and the degradation of riparian areas. Extensive water withdrawals from the Big Hole River that draw down the river to a mere trickle every summer continue to threaten the Big Hole population. Listing under the Endangered Species Act would require the creation of a federal conservation plan to address low flows in the Big Hole, among other threats.

Arctic grayling.
Arctic grayling. A primary factor in the decline of the species’ range has been the ongoing diversion of water from the grayling’s stream habitat for agricultural uses and degradation of riparian areas. (K. Sowl / 2011 USFWS Alaska Fish Photo Contest)

Case Updates

January 30, 2023 Press Release

Lawsuit Seeks Lifesaving Protections for Montana’s Arctic Grayling

Big Hole River needs curbs to irrigation withdrawals for grayling to survive

January 30, 2023 document

Arctic Grayling Complaint

Conservationists sued the U.S. Fish and Wildlife Service seeking protections for Montana’s Arctic grayling population under the Endangered Species Act. The parties — the Center for Biological Diversity, Western Watersheds Project and Butte resident Pat Munday — are represented by Earthjustice.

August 17, 2018 document

Decision: Court Overturns Denial of Endangered Species Protection for Montana Grayling

Rare fish threatened by climate change, depleted river flows