Police say a 79-year-old Montana man 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 an 18-year-old Nevada man struck the overturned trailer.
Sollis and two other people in his vehicle – two 18-year-old West Haven, Utah, residents – were taken to a hospital in Malad.
Idaho State Police say the Nevada man was later taken to the Bear River Valley Hospital in Tremonton, Utah, by ambulance. The two passengers from Utah were later flown to hospitals in their home state.
Both northbound lanes of travel were blocked for about three hours and the investigation remains ongoing.