Driver missing after vehicle plunges 300 feet off Highway 18 in Calif.

A week after their vehicle plunged roughly 300 feet off Highway 18 below the Big Bear Dam, the driver remains missing.

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The crash happened on Aug. 4 when a vehicle left the highway and came to rest hundreds of feet down a steep slope, the San Bernardino County Professional Firefighters Local 935 organization said in a news release on Monday.

Witnesses reported seeing a single occupant climb out of the vehicle and continue farther downslope, the union said. Firefighters launched a coordinated ground and air search through the rugged terrain but had not located the person by the time of the fire district’s update.

Local 935 recirculated details of the response on Monday, emphasizing that the post concerned the Aug. 4 crash and was “not a current incident alert.”

SFGATE reached out to the San Bernardino County Sheriff’s Department and the San Bernardino County Fire Protection District for further details but did not hear back before the time of publication.

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The union said incidents along mountain roads can become prolonged technical rescues because of steep terrain, requiring specialized crews, equipment, emergency medical resources and aviation support.

Officials urged motorists who travel along mountain roads to slow down, wear seat belts and avoid distractions. Anyone whose vehicle leaves the roadway should call 911 and avoid entering steep terrain unless directed by rescuers.