The cause of the Tuesday afternoon wreck hadn't been determined, but there were no indications that alcohol, drugs or excessive speed were involved, Trooper Jeff Sevigney said.
No charges had been filed.
Jeffrey B. Schrock and his children were in a southbound truck that collided with a northbound vehicle that crossed the grassy median of U.S. 395.
Authorities identified the victims as Carmen Joy Schrock, 12; Jana Louise Schrock, 10; Corina Jean Schrock, 8; Jerrill Burdiette Schrock, 5, and Creig Allen Schrock, 2. Jeffrey Schrock, 38, was in serious condition at Sacred Heart Medical Center.
The driver of the other vehicle was hospitalized in satisfactory condition.
Carmen Schrock had survived a cougar attack in 1998, during a family camping trip.
She was 5 when a cougar tore apart pieces of her skull before her mother frightened away the animal, which was later killed.