Updated

Firefighters used roads, ridges and other natural barriers to make a stand Thursday against a wildfire that threatened multimillion-dollar houses near Phoenix. In California, firefighters gained ground against a blaze that burned several homes in the Mojave Desert (search).

The windblown Arizona blaze burned at least 30,000 acres and forced the evacuation of about 250 homes. About 300 firefighters battled the blaze, with help from aircraft dropping flame retardant.

Crews set backfires to burn up brush in the flames' path, while using roads and natural barriers to direct the fire away from homes. By Thursday afternoon, the fire was moving north away from the threatened community of Tonto Hills (search), a neighborhood made up of multimillion-dollar homes about 20 miles northeast of Phoenix.

"This fire is likely going to continue to grow but it's not going to grow in directions that are going to be threatening life and property," said Art Morrison, spokesman for the fire crews.

Meanwhile, helicopters dropped water to drown the fire around nearby Camp Creek (search), an area with several cabins with many summertime residents. The area appeared to be out of danger Thursday.

Vincent Francia, the mayor of nearby Cave Creek (search), said 12 homes had been lost — two homes in the Tonto Hills area and 10 cabins in Camp Creek. Around Camp Creek, all that was left of some residences were chimneys or stoves sitting in fields of ash.

The fire began as two lightning-sparked blazes Tuesday and spread quickly in hot, dry and breezy weather.

Eric Herrman briefly returned to his $1.5 million Tonto Hills home to retrieve documents and clothing. "It's our dream home," he said. "It took us five years to build."

Herrman moved in with his in-laws in Scottsdale. "When planes started to come drop retardant on my neighbor's deck, I thought it was time to leave," he said.

Sheriff's deputies escorted people to their homes to retrieve pets, but otherwise would not allow them into the evacuated area.

In California, a wildfire that burned 3,000 acres of desert brush was 30 percent contained early Thursday. Firefighters hoped to have it surrounded by Friday.

The fire destroyed six homes and threatened as many as 700 for a time Wednesday afternoon. The flames were moving into wilderness Thursday morning, but about 200 homes were still considered to be in danger.

Fire crews in Utah and Idaho continued battling lightning-caused fires Thursday, though no structures were threatened and no one had been displaced.

Most of the fires in Idaho started Tuesday when a storm moved through the south-central part of the state, igniting grass that has flourished this year because of an unseasonably wet spring.

In southern Nevada, firefighters tried to control at least 10 lightning-sparked fires that together had burned more than 19,000 acres and cast a smoky haze over the Las Vegas Strip.

The largest charred 15,000 acres south of Las Vegas and prompted the evacuation of 100 people from a Boy Scout camp. Officials described the evacuation as a preventive measure.