Two pickups crashed on I-15 near the junction with I-86 on Tuesday afternoon.
Lonnie Cellan, 57, of Inkom, was driving southbound in a 2006 Ford F-350 pulling a trailer. Aaron Fitzsimon, 25, of Pocatello, was also southbound and was driving a 1999 Toyota pickup.
Idaho State Police said Fitzsimon struck Cellan's trailer around 1:20 p.m., causing the truck and trailer to roll into the median.
Cellan was taken to Portneuf Medical Center by ground ambulance.
The ISP did not release further information.
The crash closed a lane Tuesday, but it has since reopened.