In 1803, President Jefferson commissioned Meriwether Lewis and William Clark to find the Northwest Passage – the link between the Missouri River and the Columbia River through the unexplored Rocky Mountains. This 202-mile byway, stretching across north-central Idaho, follows the explorers' route through the ancestral homeland of the Nez Perce people.
From the west, this beautiful route begins on U.S. 12 at Lewiston, and traverses the winding Clearwater River Canyon, passing through the Nez Perce National Historical Park areas of Spalding and Kamiah and the towns of Orofino and Kooskia. At Kamiah is the Heart of the Monster, a geologic formation and legendary Nez Perce site.
At Kooskia the byway splits. One segment turns south on Idaho Highway 13 toward the Camas Prairie and the town of Grangeville. Another segment continues east on U.S. 12 along the Middle Fork of the Clearwater River, and the Lochsa Wild and Scenic River, through a magnificent wilderness culminating at the Lolo Pass Visitor Center.