Firefighters hoping for any help in stopping an aggressive wildfire northeast of Durango are looking to the debris from a massive 1998 rockslide.

The 66,310-acre blaze flared Monday, growing about 3,000 acres and forcing the evacuation of five additional housing developments.

The blaze, 30 percent contained Monday, has destroyed 45 houses and forced hundreds of people out of their homes. At its peak, it threatened more than 2,400 homes and forced almost 1,800 evacuations.

Firefighters said the old rockslide could provide the firebreak they need.

Rocks the size of train boxcars tumbled from a rim above the Animas River Valley on July 5, 1998, leaving a scar about 600 feet long and 200 feet wide.

Because of the fire's behavior in the drought-stricken region, firefighters have resorted to bold tactics such as setting backfires that for a while put a few homes at risk.

Fire managers are herding the flames toward the still-barren rockslide area.

"Our only option is to join our fire lines and the road with this chute of rock," said deputy incident commander Chris Hoff.

But there are risks. A few dozen homes are in the way.

"We have a fire we can't get close to," Hoff said. "The fuels are too dry and too thick. The terrain is too steep. The weather conditions are too severe for our firefighters on the line to make a direct attack."