The Lake County Sheriff's Office says one teen boy became wedged under a log after the plunge over the Upper Basswood Falls in the Boundary Waters Canoe Area Wilderness around 1 p.m. Tuesday.
Sheriff Casey Johnson says the falls have a drop of 25 to 30 feet.
It took over five hours for rescuers to reach and free the boy. The sheriff says the boy likely has hypothermia and an ankle fracture, but the other two are OK.
A State Patrol helicopter collected the injured youth then a seaplane flew him to Ely, where he was taken by ambulance to a hospital.
His name and condition have not been released.