Valley of Five Rivers
When Meriwether Lewis and George Rogers Clark first ventured into the Beaverhead region of the Rockies, they encountered a confusion of rivers. They saw so much moving water that they didn't know which river to choose as their navigable path over the Continental Divide. Bewildered by the options, Clark, who was sick and exhausted-in his own words, "somewhat bilious"-stayed in a camp at Three Forks while Lewis scouted the area for Shoshone Indians, whom they expected would provide horses and information that would deliver them to the Columbia drainage on the Pacific slope. At the junction of the Beaverhead and Big Hole rivers, where the Jefferson forms, the scouting party saw more beaver signs than they had ever thought possible. Lewis promptly (and mistakenly) named two of the tributaries: "[We] called the bold rapid and clear stream Wisdom and the more mild and placid on Philanthropy, in commemoration of two of those cardinal virtues, which have so eminently marked that deservedly celebrated character [Jefferson] through life." The Wisdom is now known as the Big Hole and the Philanthropy is today's Ruby. That portion of the main flow Lewis called the Jefferson was really the Beaverhead.