William Hickman, 13, had been wading in the Wallace River when he lost his footing on Saturday.
He was swept over one 10-foot waterfall, but managed to pull himself onto a narrow rock shelf just before he hit the main falls. He stayed there, cold and wet, for the next eight and a half hours.
His father shouted encouragement, telling him he was going to be OK. Crews later tossed him blankets, energy bars and fruit snacks.
After several attempts to reach him, rescuers rappelled down. One of them used a ladder to reach the boy and guide him to safety.
The Associated Press contributed to this report.