Homes ruined as blazes scorch US

Flames soar behind a vacant house near Mariposa, California, as dozens of major blazes across the US west stretch firefighters and force thousands of homeowners to flee. Photo / AP

Almost 4000 firefighters battling dozens of major fires sweeping western states.

A chimney and block wall is all that is left standing among rubble that was a house Miki Crawford and her family called home for 22 years after a wildfire raced through her community in northern California.

"Everything else is obliterated," the former nurse's aide, 56, said.

"It's just a feeling of complete devastation and loss."

Crawford said she and her husband, Jai, packed two cars with clothes, photographs, family heirlooms and their dogs and fled on Wednesday after the blaze burning in the hills near Yosemite National Park doubled in size.

Their son hiked to the area in Mt Bullion the following day and took photographs revealing a nightmare - their three-bedroom home and at least five other houses destroyed in their neighbourhood.

The aggressive wildfire sweeping through the Sierra Nevada foothills has destroyed 61 homes and 63 other buildings.

However, it spared Mariposa, a historic Gold Rush-era town popular with tourists bound for the park.

The blaze had crept within 800m of Mariposa, but crews were able to stop it by dropping red fire retardant and using bulldozers and hand crews to build fire breaks, said Cal Fire spokesman Jason Motta.

Firefighters lifted an evacuation order for Mariposa residents and reopened the highway between the town and Yosemite, California, the Department of Forestry and Fire Protection said.

The fire, one of dozens of major blazes across the US west, was 25 per cent contained by yesterday, Cal Fire said.

It has scorched 298sq km, threatened at least 1500 homes and forced almost 5000 people to flee.

More than 3800 firefighters, working in temperatures of 32C-36C, were battling the blaze, Cal Fire said.

Cal Fire's Tim Chavez blamed the fire's growth on spot fires, drought and grassy vegetation. The area's rough topography made fighting the blaze harder, he said.

The cause of the fire is under investigation.

Meanwhile, authorities say a boy smoking marijuana was arrested on suspicion of starting a small wildfire outside Sacramento.

The California Department of Forestry and Fire Protection said the 5ha fire on Friday had threatened homes and prompted temporary evacuations in the Auburn area.

- AAP, AP