Four Salt Lake County residents were injured in a head-on collision Saturday near Solitude, Big Cottonwood Canyon, tying up traffic on the road for most of the morning.

Kim Wardrop, 36, of Salt Lake City, was traveling down the canyon about 9:15 a.m. when her car collided with a vehicle driven by Mark Garff, 16, and carrying passengers Mike Kristofferson, 15, and Andrew Florence, 15, all of Holladay, said Deputy Sheriff Andy Burton.The county rescue team freed Garff, who was trapped in the car for more than an hour, said Lt. Jack Orgill of the Salt Lake County Fire Department.

A third car sustained minor damage but its occupants escaped injury when it collided with the two vehicles after the original impact, Burton said.

Garff was listed in stable condition in Cottonwood Hospital after being treated for a fractured jaw, a nursing supervisor said. Florence was taken by medical helicopter to University Hospital where he was listed in fair condition Saturday night with a fractured pelvis, a nursing supervisor said.

Wardrop was also taken by helicopter to Cottonwood Hospital, where she was listed in serious condition. Kristofferson was treated for lacerations at Cottonwood Hospital and released.

The cause of the accident is being investigated. Deputy Burton said the road was clear and dry at the time of the accident.

None of the four involved in the initial collision was wearing a seat belt, Burton said.