PORTLAND, Ore. (AP) — Crews trying to save rural dwellings in southern Oregon got help from a natural force they usually dread when winds turned around a spreading wildfire.

That kept the fire from breaking out of a 4-square-mile area near the ranching town Sprague River where crews were trying to dig containment lines, fire spokeswoman Erica Hupp said Tuesday.

The fire claimed six houses when it broke out Sunday in the Moccasin Hill subdivision, and destroyed 14 other structures such as barns and garages.

Hupp said it began expanding Monday afternoon, making a run that covered about half the length of a football field. It was in an area where bulldozers hadn’t dug lines.

The flames were moving away from Moccasin Hill, Hupp said, but if the winds hadn’t forced the fire back on itself, other homes in the area would have been threatened.

Hupp said the cause hasn’t been determined, but lightning has been ruled out. Elsewhere in Oregon and Washington state, weekend lightning has been blamed for dozens of fires.

In Northern California, a stubborn fire blamed on a truck’s exhaust threatened more than 50 homes Tuesday near the Shasta County community Igo. That was up from about 15 a day earlier, said fire spokesman Daniel Berlant.

The fire began Friday and has destroyed eight homes and 10 other structures in an area of about 10 square miles. As of Tuesday morning it was considered 20 percent contained.

A 27-year-old Sacramento man has been charged with recklessly causing the fire and with marijuana cultivation, both felonies. Authorities said he was delivering supplies to an illegal plot when the fire broke out.

In central Washington state, firefighters planned controlled burns to push back the southern end of a 35-square-mile fire near Entiat.

The fire is about 34 percent contained. But fire spokesman Daniel O’Connor says they’re having some problems with flaming debris rolling down the hill and past the southern fire line.

In Idaho, residents of about 60 homes in a small central Idaho town remained under voluntary evacuation Tuesday as crews fought nearly 20 lightning-caused fires in the Boise National Forest.

“This fire is burning in really steep country,” Berlant said. “It’s definitely a hike to get back into the area. Sprained ankles and heat exhaustion (among firefighting crews) are common.”

“It really did kind of help the firefighters,” she said.

The fire was considered 15 percent contained as of Tuesday morning, and Hupp said many residents who had been evacuated were back at home.