When Highway Patrol Officers arrived on scene around 9:30 a.m., they found a Toyota Corolla had collided into a Caltrans clean-up truck, before crashing into a Hummer. It's unclear if there were any other injuries at this time.
The left lane of northbound Highway 99 is expected to be closed for at least another hour. Officials say drivers should avoid the area due to traffic.
Stay with ABC30 for updates.