Battle to Contain Cuyamaca Blaze Half Over : Fire: More than 400 acres have burned in a timber fire started by lightning. Hundreds of firefighters are on the scene south of Julian.

Firefighters hope to fully extinguish by late tonight a timber fire that since Monday has slowly and stubbornly marched through more than 400 acres in Cuyamaca Rancho State Park south of Julian.

By Tuesday night, the fire was 85% encircled by firefighters, and was declared 50% extinguished.

Many of the towering pine trees being consumed by the blaze were already killed or diseased by pine borer beetles, said a spokesman for the California Department of Forestry.

The fire, which was ignited by a lightning strike Monday afternoon, was burning on the east side of California 79, south of Cuyamaca Lake.

“There hasn’t been a fire there in such a long time that we don’t even have a record of one,” said CDF spokesman Bob Paul.

The CDF, with assistance from San Diego City fire crews, assigned 544 firefighters to the blaze. Most had to trek into the burn area on foot because of steep terrain that barred the use of vehicles.

Aerial aid came from four helicopters delivering water drops onto the trees and four air tankers dumping chemical retardant. Many fire crews were working well ahead of the fire line, trying to establish breaks in the brush to stop the advance.

No structures were in jeopardy, and there were no injuries to firefighters Tuesday, Paul said. Monday, two firefighters suffered second-degree burns and were hospitalized, and another bruised his ribs.

Hiking trails in the area were closed, and the Green Valley Campground was closed to the public and turned over as a base camp for firefighters, who stopped at nightfall for food and rest before resuming this morning.

Paul said the thunderstorms that had settled to the east served as a two-edged sword of sorts for firefighters. While the humidity helped slow the blaze, firefighters were hampered by occasionally strong and erratic wind gusts.

“We’re counting our blessings that there weren’t any additional fires caused by lightning, and we’re hoping there won’t be any more,” he said.