Some 11,000 pounds of milk was spilled on the right eastbound lanes of Interstate 84 near the Black Cat Road overpass (milepost 41) about 7:50 Tuesday morning, snarling commuter traffic.
“The cause of the crash is still under investigation,’ said Idaho State Police spokesman Tim Marsano.
There were no reports of injuries.
The far right eastbound lane was still closed about an hour later.
The truck was carrying some 44,000 pounds of milk. Officials estimate about 25 percent of the milk -– about 11,000 pounds -– was lost, Marsano said.
“The load is measured in pounds, rather than gallons,” he added.
Crews are working to vacuum up the spilled milk.