The minors were sleeping in a tent in the Upper Pines Campground when the limb fell at approximately 5 a.m., according to park officials.
Park Rangers responded to the campsite to provide medical assistance, but found both minors to be deceased.
Authorities are not releasing the identities of the victims. The incident is under investigation.
"Our thoughts are with the families as they grieve this tragedy," Don Neubacher, park superintendent, stated in a press release.