The first American veteran on Idaho’s main stem of the Salmon

River was Captain William Clark. He and Lewis had split up to search
for a route to the Pacific, but this one was not panning out. The rapids
were too rough for the expedition’s 1,000-pound dugout canoes, and
the canyons proved too steep to portage around the whitewater. After
exploring the upper reaches in moccasins, Clark complained, “I
Sliped & bruised my leg very much on a rock.” With that, he etched
his name in a pine tree and got the heck out of there. That was in
1805.

Eventually, other   explorers,  fortune-seekers and recluses