The massive Rim Fire, now the fourth-largest wildfire in California's history, was sparked by a hunter's illegal fire, U.S. Forest Service officials said Thursday.
The fire began on Aug. 17 in the Stanislaus National Forest near the Jawbone Ridge area and has burned 237,341 acres. It is 80 percent contained.
Four Mountain View Firefighters participated in a Santa Clara County Fire strike team deployed to help contain the fire and protect structures. The 129th Rescue Wing of the California Air National Guard, based at Moffett Field, also sent two HH-60G Pave Hawk rescue helicopters to help extinguish the fire from the air.
The Forest Service announced that personnel from its Law Enforcement and Investigations division and the Tuolumne County District Attorney's Office have determined that the blaze started after the hunter "allowed an illegal fire to escape."
There is no indication that the fire is related to a marijuana-growing operation, as had been rumored, according to the Forest Service.
The hunter's name has not yet been released.
The Rim Fire destroyed the city of Berkeley's Tuolumne Family Camp, located off of state Highway 120 west of the entrance to Yosemite National Park.
As of Thursday morning, 1,900 homes were still threatened and evacuations were in effect, according to Cal Fire.