Gelernter was taken to Sevier Valley Medical Center in Richfield for treatment of undisclosed injuries.
The Jeep then struck and ran over the top of a Victory motorcycle ridden by two people. The motorcycle's gas tank ruptured and both the Jeep and motorcycle burst into flames, the UHP reported.
The driver of the Victory, Bill Mitchell, 64, and his passenger, Diane Mitchell, 64, both of Tuscon, Ariz., were killed.
The driver of the Jeep, who was not wearing a seat belt, was ejected. He also was taken to Sevier Valley Medical Center for treatment.
The UHP reported that the Mitchells and Gelernter were riding as a group with two other motorcycle riders. The other riders steered left into the eastbound lane to avoid colliding with the Jeep.
The teen lost control of the Jeep when it drifted left and he over-corrected to the right, the UHP reported.
The Jeep then ran off the right shoulder and struck a guardrail.
The teen then corrected back to the left,crossing the center line into the westbound lanes, where he collided with the motorcycles.
The cause of the crash remained under investigation Thursday evening. But excessive speed and driver impairment were not considered to have been contributing factors, the UHP reported.