Video obtained by ABC13 shows the smoke coming from the trailer, along Highway 225 at Red Bluff, just before 1 a.m.
Firefighters said the driver had just picked up the trailer from the port. Then, the trailer started experiencing mechanical issues, causing a tire to blow up and have problems braking. It ultimately overheated.
It was full of clothing that was supposed to be delivered to a store, according to firefighters at the scene.
Thankfully, there were no injuries.
The westbound lanes reopened at about 5:30 a.m.