A preliminary investigation indicated the fire started Sunday from a catalytic converter, said Nancy L. Joseph, a Department of Natural Resources spokeswoman.

"It's another example why people need to be careful," Joseph said Wednesday. "Something as simple as parking a car or running a car on real dry grass can start a fire."

About 70 firefighters dug trails and poured water on the flames Wednesday while a helicopter was used to drop 100-gallon buckets of water onto hot spots. The fire was 75 percent contained with the remainder along a steep, wooded ridge, that is making the fire hard to completely extinguish.

"We just can't get people directly in the fire because there's a lot of things rolling down the hill," Joseph said. "Safety of firefighters is paramount."