The Chimney Fire, which burned more than 46,000 acres and destroyed 70 structures near Lake Nacimiento and the surrounding areas, was started by a vehicle, Cal Fire investigators have determined.

According to a Cal Fire news release dated March 29, investigators concluded that a vehicle ignited dry grasses adjacent to a dirt road, starting the blaze.

Investigators dispatched as part of the initial response to the fire “immediately began working to determine the origin and cause of the fire,” the news release said.

“The ensuing investigation showed contact between a vehicle and dry grass to be the sole cause of the fire that started Aug. 23, 2016, at 4:03 p.m. near Running Deer Road and Chimney Rock Road, south of Lake Nacimiento,” the release said.

The Chimney Fire, which lasted 25 days, burned 46,343 acres of land and destroyed 49 homes, along with 21 other buildings.

Flames along the Santa Lucia ridgeline were visible from Highway 1 at times, and the fire came within 2 miles of Hearst Castle. 

The historic museum was closed from Aug. 20 through Aug. 28 because of heavy smoke and the threat of the fire.

At its peak, more than 3,943 firefighters battled the fire, which was declared fully contained Sept. 6.

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