"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."
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.
Westslope cutthroat, small trout with a rosy underside and dark speckled tail, live mainly in Montana, Idaho, and Canada, with small numbers in Washington, Wyoming, and Oregon. They persist wherever there are cold clear streams for them to spawn in and deep sheltered pools where they can wait out the winter. In the spring, as snowmelt swells rivers and streams, cutthroat return to tributaries to mate and lay eggs. Some migrate more than 100 miles to a suitable spawning site; others stay in the area where they live year-round.