"The specks on these are of a deep black..."

"Goodrich had caught half a dozen very fine trout and a number of both species of the white fish. These trout are from sixteen to twenty-three inches in length, precisely resemble our mountain or speckled trout in the form and the position of their fins, but the specks on these are of a deep black instead of the red or gould colour of those common to the U' States." -Meriwether Lewis

On June 13, 1805, Lewis witnessed a scene that he described as "the grandest sight I ever beheld." He spent paragraph after paragraph in his journal painting the splendor of the Great Falls of the Missouri (at a place that would later become Great Falls, Montana) and then, frustrated at his inability to capture the beauty in words, wondered if he shouldn't cross it all out and start over. The waters of the Great Falls also provided a glimpse of a species new to science: the westslope cutthroat trout. Private Silas Goodrich caught some for dinner, and before Lewis took a bite, he noted the appearance, partaking in a great tradition that Charles Darwin would also employ: dinner-table natural history. Two centuries of dams and water diversion have tamed the roaring wall of water that so impressed Lewis. The spot he admired is now the site of the Ryan Dam. Westslope cutthroat trout, which honors both explorers in its scientific name, Oncorhynchus clarki lewisi, is found in only a fraction of its historic range.

Tracking the changes

In Idaho, where the cutthroat is the state fish, westslope cutthroat were once the most common trout species in the central and northern parts of the state. In recent decades, populations have declined. Westslope cutthroat are easily disturbed by logging and roadbuilding, which muddy pristine streams and remove shade trees that cool the water. A recent study by the Western Native Trout Campaign showed a strong correlation between roadless areas and the survival of native trout populations.

Non-native fish, both stocked and accidentally introduced, pose additional problems. Some, like northern pike and lake trout, eat cutthroat trout. Others, like brook trout, outcompete the cutthroat for food when the two share a stream. Still others, like non-native rainbow trout, hybridize with cutthroat, diluting native gene pools. While some estimates place the fish in 19 to 27 percent of their original range in Montana and 36 percent of their original range in Idaho, unhybridized cutthroat strains occupy only 2 to 4 percent of their traditional habitat.

In 2000, the U.S. Fish and Wildlife Service declined to protect westslope cutthroat under the Endangered Species Act. The Alvord cutthroat and yellowfin cutthroat, two other subspecies, have already gone extinct.