The US's largest wildfire has forced more than 1,500 people from their homes and cabins in a southern Utah mountain area which is home to a ski town and popular fishing lake.
Firefighters battled high winds as they fought a blaze that has grown to 72 square miles (184 sq km) and burned 13 homes - larger than any other fire in the country now, state emergency managers said.
Some flames reached 100ft (30m) high, while fire crews faced dry, windy conditions on Tuesday and a "high potential" for extreme fire behaviour, officials said late on Monday.
The estimated firefighting costs now top 7 million US dollars (£5.5 million) for a fire which started on June 17 near the Brian Head Resort by someone using a torch tool to burn weeds, they said. Investigators said they know who the culprit is, but they have not yet released the person's identity or what charges will be levelled.
Crews in California, meanwhile, had to deal with two new powerful and fast-growing fires, and Arizona firefighters had to ground aircraft because of unauthorised drones over a blaze near Flagstaff.
The Utah fire began near the ski resort town of Brian Head, generally known for weekend getaway homes for Las Vegas residents. It has spread several miles east to an area around Panguitch Lake, a popular spot for fishing.
Authorities ordered more evacuations in a sparsely populated area on Monday as stronger winds and lower humidity develop which could push fire growth north after calmer weather kept its growth in check over the weekend. The fire is about 10% contained.
About 175 people have been briefly allowed back to their homes near Panguitch Lake since Sunday under escort, said Denise Dastrup, from the Garfield County Sheriff's Office.
Randi Powell said her grandfather is hoping to get up to see his cabin on Tuesday. She said it has been an "emotional rollercoaster" for her and her grandparents, who live part of the year at a cabin near the fire.
Ms Powell said she and her sister helped grab family heirlooms, pictures and important documents last Thursday when her grandparents had to evacuate at short notice.
She is relying on social media updates from friends and others who live or have homes in the area. So far, it appears her grandparents' five-bedroom cabin, built about 60 years ago, is still intact, she said. But that has not stopped them worrying.
"There will be uncertainty until you get up there and walk through it," said Ms Powell, 32, who lives about one hour away in Cedar City. "Until it's totally out, you won't know if you'll be OK."
At Brian Head Resort, they are hoping that hot spots near where the blaze started will calm down enough to allow officials to lift the evacuations in time for 4th of July festivities that usually bring an estimated 15,000 people to listen to music and watch fireworks, resort spokesman Mark Wilder said.
If the events can happen, they are likely to be scaled back with fewer visitors - and with no fireworks, he said, adding that they are hopeful but realistic.
"Things change day to day," Mr Wilder said. "This thing has been a beast."
Meanwhile, a wildfire surging out of control on California's Central Coast has forced about 250 people to evacuate from their homes.
The blaze broke out late on Monday afternoon and quickly grew to nearly 1.5 square miles (200 hectares), the California Department of Forestry and Fire Protection said.
The evacuation order is for a string of homes along sparsely populated rural roads in and around the small town of Santa Margarita about 10 miles (16km) north of the much larger city of San Luis Obispo. The fire has grown to nearly two square miles (365 hectares).
Another California wildfire, sparked by a traffic accident on a remote stretch of highway 80 miles (129km) east of Los Angeles, has grown to nearly two square miles (more than 500 hectares) in just a few hours. The blaze was 10% contained.
Two people were taken to hospital after the crash and subsequent car blaze that caused the wildfire on Monday afternoon.
Both California fires came amid soaring temperatures and dry air that are expected to start receding early on Tuesday.
In New Mexico, Governor Susana Martinez ordered flags to fly at half-mast in honour of a volunteer firefighter who died from injuries suffered while battling a brush fire in eastern New Mexico last week.
Nara Visa Fire Chief Gary Girard told The Eastern New Mexico News that John Cammack was severely burned after falling from a fire engine when the winds shifted and the flames changed direction.
In Arizona, firefighters had to ground aircraft after they spotted drones being flown near the fire, Bureau of Land Management spokesman Dennis Godfrey said.
The Arizona Republic reported that another unauthorised drone was spotted on Sunday, temporarily halting aerial efforts to put out a fire northwest of Flagstaff that is 88% contained.