SIERRA COUNTY (CBS13) – Search parties are trying to find an Alameda County family overdue from camping trip in Sierra County.

The Sierra County Sheriff’s Office says Nicholas Vlahos, a 41-year-old man from Oakland, and his two young children, a 5-year-old son and 3-year-old daughter, were reported missing Tuesday night after not coming home from a camping trip in western Sierra County.

The trio was camping with other family members and were last seen in a black 2015 Toyota Tundra 4X4.

Authorities believe the father decided to take a rugged and remote part of Sierra and Plumas counties on the way back home. They have not been heard from since.

Search parties from the sheriff’s office, along with Cal Fire and California Highway Patrol, have been looking at the intended route and surrounding areas. More searches are scheduled through Thursday.