District headquarters received a report of a missing hiker in Ohlone Regional Wilderness at about 8 p.m. Wednesday, the dispatcher said.
The man had been hiking with a friend into Ohlone from Sunol Regional Wilderness in southern Alameda County when he became fatigued and could not continue to hike out.
His friend left the man to get help and authorities began a search that continued into this morning. Teams from the Alameda County Sheriff's Office assisted park police in the search.
