A northern Arizona wildfire between Sedona and Flagstaff ripped through heavily forested Oak Creek Canyon and burned more than 4,500 acres by Wednesday evening, officials said.
Vacation cabins, homes and businesses on the north end of Slide Rock State Park had been evacuated and were among 300 structures under threat. Officials warned the communities of Kachina Village and Forest Highlands that they could be next.
The picturesque area is popular among campers and hikers, many of whom were expected to come for the long Memorial Day weekend.
The Slide fire was reported about 4 p.m. Tuesday. It is being investigated as human-caused because lightning wasn't an issue at the time, said Heather Noel, a spokeswoman for Coconino National Forest. Authorities did not have any immediate leads.
The fire began just north of Slide Rock State Park and has been traveling northward through the canyon, fueled by humidity near 15% and gusts of about 30 mph.
Among those evacuated were campers, who were taken to a shelter at Sinagua Middle School in Flagstaff, where smoke from the fire created hazy conditions. The American Red Cross provided meals and clothing to the campers, organization officials said.
"I have a feeling our trip will have to be canceled," she said by phone Wednesday. "This is just devastating for people who know these cabins. There's a lot of history there."
"I'm just hoping nothing happens to those cabins," Lwin said, noting that her honeymoon was spent at the Butterfly Garden. "It's an all-natural environment around there, and now it's all gone because of a human."
More than 500 people were helping to fight the blaze, including some firefighters who worked on wildfires that took out several thousand acres in San Diego a week ago.
Noel said authorities suspect the fire was sparked in Oak Creek Canyon between Flood Rock and Halfway Picnic Area.
On Tuesday, the U.S. Forest Service said it added four more aircraft to its fleet to contend with "what is shaping up to be a catastrophic fire season in the Southwest."
The agency blamed climate change, forest diseases and suburban sprawl for extending the annual fire season by more than two months during the last 30 years.
In the upper West, from Idaho to the Dakotas, the Forest Service on Monday indefinitely banned the use of exploding gun targets because such devices have started at least 16 wildfires in the West during the last two years. A similar ban took effect last year in the Rocky Mountain region, including Colorado, Wyoming and Nebraska.