A tractor-trailer slid off the freeway near Kellogg early Sunday, spilling more than 200 gallons of diesel fuel.
The driver, Kenneth James Barnard, 35, of Portland, was taken to Shoshone Medical Center in Kellogg. He was treated and released.
Barnard was eastbound on Interstate 90 when he lost control of the truck at 4:35 a.m., according to the Idaho State Police. The trailer slid, causing the tractor to go off the right side of the road and strike a guardrail.
The guardrail punctured the fuel tanks, authorities said.
Shoshone County firefighters mopped up the spill, said ISP Cpl. James Culpepper.
Barnard was cited for driving too fast for conditions, Culpepper said.