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.

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

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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.

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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.