Idaho State Police are investigating a two-vehicle crash near Blackfoot.
ISP says Boyd Gettman, 47 of Pocatello, was traveling west in a 2000 Ford Expedition on N 100 W, when he didn't yield at a stop sign and crashed into a 1980 Harley Davidson that was heading north on US 91.
Officers say the motorcyclist is 60-year-old Kenneth Sellers from Blackfoot.
The driver of the motorcycle was airlifted to the Eastern Idaho Regional Medical Center with unknown injuries.
ISP says both northbound and southbound lanes on US 91 were blocked for a couple of hours, but are back open.