The Sûreté du Québec (SQ) officers were called around 9 a.m. Sunday after a local spotted a body in the the Rivière du Nord.
Police recovered the body and later confirmed it was the girl that went missing on May 12.
The teenage victim, whose identity has not been made public, was standing on rocks with three other people under a bridge when she allegedly slipped and fell into the water.
Rescue teams were deployed, including a dive team, firefighters and a helicopter.
Authorities say they are trying to determine the circumstances surrounding the death.
— With files from the Canadian Press