A sheriff's deputy spotted a vehicle off the roadway at about 11:30 a.m. today in an unincorporated area near Three Springs Road.
Firefighters from San Jose and Cal Fire launched an effort to determine whether anyone was inside what was initially believed to be just one car, but Rangel said no one was located.
He noted that the area can be dangerous for drivers.
"Mt. Hamilton has got some very steep dropoff areas," he said.