A head-on collision near Collins Lake in Yuba County on Monday left multiple people injured, the California Highway Patrol said.

It happened around 5:15 p.m. on Marysville Road near Leanne Way, on the northwest side of the lake, when a 56-year-old woman driving a silver Toyota Corolla northbound drifted into the oncoming lane and collided head-on with another silver Toyota Corolla traveling south, the CHP's Yuba-Sutter division said.

The female driver who veered into the wrong lane suffered major injuries and was airlifted to a Chico hospital. The other driver was a 53-year-old man who was airlifted to a Roseville hospital with a broken arm and other serious injuries. As of Thursday, the CHP said both drivers remained in critical condition.

Investigators said it appears the woman may have fallen asleep behind the wheel.  

A 36-year-old woman and three children riding in the man's car sustained minor injuries. Among the three children were two girls, ages 11 and 9, and a 13-year-old boy, the CHP said.

All three were transported to a Yuba City hospital for treatment.  

Emergency crews closed Marysville Road for nearly two hours to investigate the crash and clear the scene.

The incident remains under investigation by the CHP. It's not yet known what caused the woman to drift into oncoming traffic.