Police say 79-year-old Ronald Lane of Virginia City, Montana, was traveling north on I-15 in a semi-truck pulling two trailers when he left the roadway and went into the median.
Lane reportedly came back onto the roadway but one of his trailers overturned into the left lane.
A northbound vehicle driven by 18-year-old Jayden Sollis of Henderson, Nevada, struck the overturned trailer.
Sollis and two other people in his vehicle – 18-year-old Shelby Widdison and 18-year-old Gavin Bass, both of West Haven, Utah – were taken to a hospital in Malad.
Idaho State Police say Sollis was later taken to the Bear River Valley Hospital in Tremonton, Utah, by ambulance. Widdison was flown to the University of Utah hospital while Bass was flown to McKay-Dee Hospital in Ogden.
Both northbound lanes of travel were blocked for about three hours and the investigation remains ongoing.