Authorities in California ordered residents to evacuate the scenic Big Sur coastal area on Wednesday to allow firefighters sole use of narrow roads to battle a stubborn wildfire in the steep terrain.

"The firefighters need to move their equipment there," said Maia Carroll, a spokeswoman for Monterey County. "We can't have residents going down and fire equipment going up at the same time."

The evacuation order for some 850 residents and the area's inns and campgrounds followed the blaze jumping a defense line, which required crews to rush equipment to the scene, Carroll said.

The fire has burned more than 52,000 acres (21,045 hectares) since breaking out on June 21.

Firefighters have managed to contain only 3 percent of the blaze, which is threatening nearly 1,300 structures, as the Big Sur region's steep slopes along California's central coast impede efforts to control the blaze. Thick dry vegetation, winds and warm weather have added to firefighters' troubles.

Seventeen structures have been destroyed by the fire, which roughly 1,550 firefighters and other personnel are battling, backed by 69 engines, eight helicopters and seven air tankers.

California Gov. Arnold Schwarzenegger and Federal Emergency Management Agency chief David Paulison visited Big Sur on Wednesday for a briefing on the status of the fire, one of many large blazes across California.

Schwarzenegger said more than 19,000 firefighters and other personnel have contained 85 percent of the hundreds of fires sparked two weeks ago, mostly by a wave of lightning strikes.

"We have 1,416 engines that are working on those fires and more than 100 helicopters and fixed-wing aircraft also are out there helping with this effort," he said.

Another major fire is raging east of Big Sur in the Ventana Wilderness and the Los Padres National Forest. At the forest's southern end, a fire near Santa Barbara has forced homeowners to evacuate.