Authorities are attributing the incident to arson after an analysis showed indications of gasoline inside the SUV, according to the San Mateo County Sheriff's Office.
Firefighters, medics and the county's hazardous materials team were called in after Deputy Stephen Duvall, in his approach to the parked SUV at 11:40 p.m., noticed a chemical smell and saw a thick plume of smoke inside, so thick that it concealed what was going on in there, the Sheriff's Office said.
Deputy Duvall quickly backed away from the vehicle to avoid inhaling the fumes, but medics took him to San Mateo County General Hospital anyway as a precaution, the Sheriff's Office said. The vehicle was unoccupied and there were no injuries reported.
Deputies closed the section of Alpine Road between Westridge Drive and Arastradero Road for about two and a half hours while the crews dealt with the fire and its aftermath.
The vehicle was towed and normal traffic resumed at 2:20 a.m., the Sheriff's Office said. Authorities were unable to reach the vehicle's owner.
Deputies are asking anyone with information about this incident to call Sheriff's Office Detective Marcus Gathright at 363-7823 or the anonymous tip line at (800) 547-2700.