PRESCOTT VALLEY, Ariz. -- A wildfire burning Wednesday through a dense Arizona forest has forced thousands of people from their homes, closed a major road and created a huge plume of smoke over the same area devastated by a blaze that killed 19 firefighters four years ago.

The fire is burning in communities around Prescott, a mountain city about 160.9 kilometres north of Phoenix that draws a mix of desert dwellers escaping the heat, retirees and visitors to its famed Old West-themed Whiskey Row.

The fire has charred 83 square kilometres while being fanned by winds ranging to 56 kph winds.

More than 500 firefighters were battling the blaze. A firefighter suffered a minor injury.

The fire forced the evacuation of Mayer and Dewey-Humboldt along with several other communities, and one of the main roads into Prescott was closed. Dewey-Humboldt has about 4,000 residents; Mayer has about 1,400.

Many residents have painful memories of the 2013 wildfire that killed 19 members of an elite firefighting crew.

"It's scary because we're coming up on the four-year anniversary of the Yarnell Hill fire -- there's still a lot of fresh memories," said Arizona state Sen. Karen Fann, who lives in Prescott and represents the area where the fire is burning.

Elsewhere across the western U.S., a fire in the foothills north of Los Angeles was burning right up to homes.

Dozens of homes were under mandatory evacuation orders on the suburban edges of Burbank, where flames raced uphill through tinder-dry grass.

No homes have been reported destroyed but flames were spotted in or near backyards.

In Central California, a wildfire destroyed the home of "Big Bang Theory" star Johnny Galecki on a ranch in the San Luis Obispo area.

In Utah, firefighters braced for more high winds as they tried to slow a stubborn wildfire that has burned 13 homes and forced the evacuation of 1,500 people from a ski resort town.

Firefighters in Washington state were battling three fires near Wenatchee that had grown to about 95 square kilometres.

And in Idaho, fire officials say quick responses by ranchers and others to more than 20 wildfires sparked by lightning have kept the small fires from becoming major blazes like those that scorched the region in recent decades.

In Arizona, Jennifer Johnson of Phoenix was driving into Prescott Valley Tuesday for a meeting and noticed smoke on the way in. By the time the meeting wrapped up a few hours later, things had changed dramatically.

"Getting closer to Mayer, it looked like we were driving into some alien sort of invasion, like the whole sky was on fire," she said.

Video she took along the freeway shows huge clouds of smoke colored red by flames.

Arizona Gov. Doug Ducey plans to visit the area Thursday after declaring a state of emergency in Yavapai County that directs $200,000 in emergency funds to fire suppression efforts and reimbursements for emergency response and recovery costs.

It's also a key requirement should federal aid resources be requested.

The blaze is burning in thick chaparral that has not seen a fire in more than 40 years. The steep, rugged terrain makes it difficult for firefighters to reach.

Mayer resident Jill Baker fled town after learning of evacuations on Tuesday while filling up her tank at a gas station. She grabbed her three dogs and rushed to a nearby high school in Prescott Valley, sleeping on a cot and eating Subway sandwiches.

As she left town, she said, residents were pulling off on the side of the road and discussing what to do about their belongings, pets and horses.

"It looked like five fires," Baker said. "We were probably seven miles from the actual fire and it was pretty scary."

Yavapai County Emergency Management Coordinator Denny Foulk said there are about 2,000 residents in the area affected by the fire and 3,000 structures in the evacuated area were at risk but officials were not immediately sure how many are homes.

"Yesterday you could not smell it, which means it was probably blowing away from us," Dewey-Humboldt resident Zerril Perkins said. "Now you can smell it so that's a little worrisome because it might be blowing toward us."

He and his wife were packed and ready to head to Phoenix if necessary.

AP writers Clarice Silber, Josh Hoffner and Bob Christie contributed from Phoenix.