The crash was reported at about 6:10 a.m. near Napa Valley College on Highway 221 at Magnolia Drive, CHP Officer Peter Van Eckhardt said.
A vehicle apparently rear-ended the big-rig, causing the CHP to shut down both northbound lanes of the highway. At least one person suffered major injuries and was taken to a hospital, Van Eckhardt said.
A Sig-alert was issued at about 6:30 a.m. and was canceled at about 7 a.m. when the lanes were reopened.
