MESA VERDE NATIONAL PARK, Colo. - A fast-moving wildfire more than doubled in size Friday, rampaging up steep canyon walls and spreading across 3,500 acres at Mesa Verde National Park.
About 350 firefighters backed by slurry-dropping planes and helicopters were on the scene, and the park remained closed for a second day.
The fire was burning juniper, pinon and oak brush in rugged terrain on the eastern boundary of the park, about 260 miles southwest of Denver.
The canyon walls are so steep that firefighters had difficulty reaching the flames. Officials said the fire was so intense it was creating powerful updrafts, in effect making its own weather rather than being pushed by winds.
The fire, which started the day at 1,500 acres, was only 5 percent contained by nightfall Friday, said Justin Dombrowski, spokesman for an interagency firefighting team.
No injuries were reported, and none of Mesa Verde's ancient Indian ruins was damaged.
Clouds of gray and white smoke boiled up over the hills and mesas Friday.
''Oh, my! It's grown,'' said Jane Anderson, who works for the park and lives nearby. ''I have this notch (in a ridge) that I've been keeping my eye on. Yesterday, the fire had crept close and today it had gone past,'' she said.
Officials closed the park Thursday afternoon as the fire grew from 50 acres to 500 acres in about three hours and threatened to cut off the only road into the area. About 1,000 tourists were evacuated, but a few stayed behind at the Far View Lodge.
Administrators did not know when the park might reopen.
The fire, apparently caused by lightning, started on private land and spread into the park.
Ancestral Pueblo Indians built cliff dwellings in the canyon walls of Mesa Verde. The 52,000-acre park, established by Congress in 1906, was the first cultural park in the National Park system. There were about 650,000 visitors last year.
Meanwhile, another fire burned through the Paiute Wilderness area of the Virgin Mountains in northwestern Arizona.
The fire had burned at least 100 acres controlled by the Bureau of Land Management in Elbow Canyon, 10 miles southeast of Mesquite, Nev., said fire information officer Teresa Rigby. It was growing as strong winds carried flames through the steep rocky canyon.
The blaze was started by a person in prime wilderness habitat for bighorn sheep, Rigby said.
Nearly 56,000 fires have burned 2.8 million acres nationwide so far this season, according Friday figures from the National Interagency Fire Center in Idaho. That is the worst acreage total since 1996.
On the Net:
Fire center: http://www.nifc.gov
Mesa Verde National Park: http://www.nps.gov/meve/