A Cal Fire San Diego truck on a rural road. (File photo courtesy Cal Fire)
A Cal Fire San Diego truck on a rural road. (File photo courtesy Cal Fire)

Crews continued working overnight to contain the smoldering remains of a wildfire that blackened hundreds of acres in a rural area near Golden Acorn Casino, spreading perilously close to back-country neighborhoods but damaging no homes.

As of Thursday morning, the roughly 820-acre non-injury fire, which burned west of Ribbonwood Road, was more than 70% contained, Cal Fire said.

The fire first erupted for as-yet unknown reasons at about 1 p.m. Tuesday off the 37000 block of Tusil Road, just north of I-8 in Boulevard.

Within two hours, the fast-moving flames had charred several dozen acres on the grounds of Campo Indian Reservation and were moving south toward the freeway, officials said.

The California Highway Patrol shut down a stretch of the freeway in the area as ground crews and personnel aboard air tankers and water-dropping helicopters battled the blaze.

By late afternoon Tuesday, the blaze had jumped Interstate 8 in a few spots and had damaged one outbuilding and a vehicle.

Sheriff’s deputies cleared people out of residences on both sides of the freeway in the area of Old Highway 80, officials said. A temporary shelter for the displaced was available at the casino at 1800 Golden Acorn Way, a mile or so east of the fire.

Some 178 personnel were assigned to the fire, including 25 engines, seven hand crews and two helicopters, officials reported. At least 12 additional agencies were assisting in the effort.

The cause of the fire was under investigation.