Hundreds of firefighters and a fleet of aircraft battled a 1,400-acre fire tearing through coastal canyons in California on Thursday as blazes in Arizona and New Mexico threatened communities with thousands of residents.
Hot, dry weather across the Western U.S. challenged firefighters.
In California, crews for a second day struggled to douse flames amid rugged coastal canyons west of Santa Barbara where brush hasn't burned for 60 years.
About 140 homes and ranches were potentially at risk, depending on which way winds pushed the flames.
"Sundowner" winds that rose at nightfall Wednesday spread the fire and authorities feared a repeat as winds began to pick up Thursday night.
"If that happens, it's going to be a major battle" to protect homes, said Gina DePinto, communications manager for Santa Barbara County.
The fire was expanding and a freeway, U.S. 101, was closed for a second night.
About 800 firefighters and a fleet of aircraft were assigned to the battle.
Several campgrounds remained evacuated, although nobody remained at shelters. A convention group at one campground got Uber rides to leave the area, said Susan Klein-Rothschild with the county health department.
Charlie and Elizabeth Hatten spent the night at a shelter Wednesday night after a park ranger woke them as they camped at El Capitan State Beach.
"The flames looked so close. You couldn't see the moon anymore," Charlie Hatten told the Los Angeles Times.
In central New Mexico, firefighters struggled to make progress against a blaze that exploded to 25 square miles and forced residents of some small communities to flee after sending up a towering plume of smoke that blanketed the state's largest city in a thick haze.
Some structures burned near the small community of Chilili, but it was not clear whether they were homes.
The community was among those in Bernalillo and Torrance counties placed under a mandatory evacuation order as flames raced northeast.
In east-central Arizona, a small community was evacuated and thousands of other residents were told to prepare to leave after a wind-whipped wildfire charred more than 12 square miles.
However, fire lines were holding Thursday.
"The winds weren't as bad, and the back-burns did exactly what we wanted them to do," Navajo County Sheriff KC Clark said at a late afternoon news conference.
The fire broke out Wednesday 12 miles south of Show Low. Gusty winds pushed it into brush and ponderosa pine.
In Nevada, a 300-acre Reno brush fire that threatened dozens of homes was 75 percent contained and crews were mostly in mop-up mode Thursday evening.
Blazes also threatened homes in Utah, where a firefighter hurt his head in a fall.