All three teens were taken to Queen of the Valley Medical Center in Napa.
The 17-year-old driver of the 1990 Toyota pickup suffered minor injuries and was arrested on suspicion of DUI.
A 17-year-old passenger suffered major injuries and was listed in critical condition, CHP Officer A. Paulson said. The names of the juveniles were not released.
Passenger Dustin M. Rossrubio suffered minor injuries, the CHP said.
The driver was heading north on Dry Creek Road north of Orchard Avenue in unincorporated Napa County around 4:40 a.m. when he allowed the truck to drift east and off the road, the CHP said.
The truck sideswiped a metal fence post, collided with one tree then stuck a second tree head-on.
The crash closed Dry Creek Road for two hours.
