A 17-year-old Great Falls boy died while cliff jumping into the Missouri River north of Helena on Saturday afternoon.
Lewis and Clark County Sheriff Leo Dutton said David Delcomte jumped off a roughly 40-foot cliff while boating with his family near Gates of the Mountains just before 3 p.m. An outcrop of rocks was not visible from the surface, Dutton said.
"His father dove in after David did not surface and made a valiant effort to find his son, but to no avail," Dutton said.
There is no cellphone service in the area, Dutton said, but a Gates of the Mountains tour boat was passing by and radioed for help.
Search and rescue divers later found the teen's body in about 30 feet of water just south of Mann Gulch, Dutton said.
Delcomte's cause of death has not yet been determined. An autopsy in Missoula is planned.