The crash, which was reported at 9:54 a.m. in the northbound lanes just north of Marsh Road, had blocked both north- and southbound lanes and backed up traffic for miles.
Preliminary reports indicate that the collision involved a jackknifed big-rig and up to eight other vehicles, according to CHP.
The CHP reported at least 20 gallons of diesel fuel spilled as a result of the crash, but it was not declared a hazardous materials situation.
A Sig-alert was issued at 10:07 a.m. and canceled at 12:22 p.m.