Six semis and a car were crashed on Highway 395 north of Pasco late Monday afternoon.
Northbound lanes reopened shortly before 7 p.m., while one southbound lane was open near the Highway 17 Mesa exit, Trooper Chris Thorson of the Washington State Patrol said on social media.
Thorson earlier said he expected the southbound highway to be closed for two to three hours after a wrong-way semi truck caused a pileup of four semis.
Another crash in the southbound lanes involved two more semis and a car.
At least one person was hurt in that crash, but no more information was available Monday evening.
Kirk Andersen, of West Richland, and his wife had been stopped on the highway for two hours by 6:30 p.m.
He said the roadway was a sheet of ice and his car fishtailed when he came upon the first crash. The highway should have been better maintained, he said.