TWINFALLS -- Heavy fog and icy conditions on Interstate 84 sent drivers spinning into the ditch just before 11 a.m. on Thursday east of Twin Falls.
Idaho State Police says a chain reaction involved eight semitrailers and nine cars in separate crashes near Hazelton.
No injuries were reported.
The Idaho Transportation Department says the freeway is now open in both directions but the roadway is reduced to one lane.
The interstate was closed Thursday for about six hours.
ISP says eastbound lanes will be down to one lane between mile posts 188 and 194 until sometime Friday as crews work to clean up debris and remove some of the vehicles involved in the crashes.
ITD Communications Specialist, Mel Coulter, says the driving conditions were among the worst in the state, with visibility hampered by fog throughout Thursday morning.
The interstate is still wet in the area and could refreeze overnight so ISP is asking drivers to be cautious.
For current traffic reports, check KTVB's road conditions page here.