GOLDEN, Colo. — About 8,500 people were ordered to leave their homes Thursday as the second major wildfire to erupt this week in an outlying Denver suburb blackened 2.5 square miles.
Officials ordered the evacuation of homes within a 4-mile radius of the fire near Franktown, about 35 miles southeast of Denver.
High winds quickly spread the fire through grasses, brush and trees dried out from months of below-normal moisture. Strong winds fueled several grass fires on the eastern plains, including one that charred 8 square miles 95 miles southeast of Denver and burned two wooden bridges and a barn.
The fire near Franktown started Thursday afternoon in a wooded area and grew to about 1,600 acres by late afternoon. Crews contained 70 percent of the fire by early evening, and all residents were allowed to go home Thursday night with the warning to be ready to leave again if necessary.
Several homes were threatened, but none have been damaged, fire officials said.
Smoke from the blaze was visible from south Denver suburbs, and a helicopter was dropping water on the flames. A Red Cross evacuation center was set up at the Douglas County fairgrounds for people and at least 100 horses that were evacuated. The animals had to stay overnight.
It's not known how the blaze started, but it burned erratically, creeping right up to a high school that fire officials were using as a headquarters.
Video from Denver TV stations showed a row of flames sweeping up to a fence line and a firefighter hosing down a house, barn and a horse and other animals running around. A helicopter then hit the fire with a load of water and doused the flames.
Gracie Tynecki, 14, was home alone on spring break when she got a reverse 911 call warning of the fire.
"I immediately freaked out," Tynecki said.
She ran to a neighbor's house where a friend was also home alone. When Tynecki's mother made it home, the two grabbed computers, jewelry, a baseball signed by former Colorado Rockies player Larry Walker and their dogs before leaving
"It was a fearful day," said Tynecki, among those who got to go home Thursday evening.
The other wildfire has charred a little more than 2.6 square miles in rugged canyons just outside Golden, about 15 miles west of downtown Denver. That fire was nearly 80 percent contained Thursday evening and some of crews on that fire switched over to the Franktown wildfire.
Authorities said 289 homes are in the immediate area but none are considered threatened. No homes have been destroyed, and evacuation orders have been lifted.
U.S. 6, a busy highway that connects Denver with the casino towns of Blackhawk and Central City, was shut down because of heavy fire-truck traffic. It will remain closed until engineers can determine whether helicopter water drops have loosened any rocks and left them in danger of tumbling onto the road.
Colorado Transportation Department spokeswoman Stacey Stegman said she didn't know when the inspection would be done.
Gov. John Hickenlooper issued an emergency disaster declaration Thursday, allowing the state to spend up to $1.5 million to cover firefighting costs. It also opens the door to asking for federal help, if necessary.
Winds and extremely dry weather helped the Golden fire spread quickly when it started Sunday. Since then, wind has periodically grounded the helicopters that drop water on the blaze, now listed at 1,700 acres and 77 percent contained.
Investigators concluded the fire near Golden was human-caused and are asking for help from the public to find out who started it. They set up a tip line to take information about any suspicious activity in the area on Sunday.
The wildfire risk was high from central Colorado south into northern New Mexico, prompting the National Weather Service to issue a red-flag warning for the area Thursday.
Wildfires are common in Colorado this time of year, when winds are strong and vegetation is dry. Compounding that is a severe drought affecting most of Colorado east of the Rocky Mountains, including the Denver metropolitan area.
Incident commander Rowdy Muir, who has been in the job for nine years, said this is the earliest his team has ever been mobilized. Colorado could be in for a repeat of the 2002 season, when the largest wildfire in state history burned 215 square miles, he said. A total of 515 square miles burned statewide that year.
State climatologist Nolan Doesken said precipitation in the foothills and on Colorado's Eastern Plains has been at 50 percent of average or below since August.
At least five Colorado counties have enacted fire bans.
On Colorado's eastern plains, a grass fire fed by winds burned two bridges and a barn near the Lincoln County town of Karval, said sheriff's Capt. Clint Tweden. Plans to evacuate the town of about 100 were canceled when the 8-square-mile blaze changed direction.
In southern Colorado, about 40 firefighters battled a nearly 8-square-mile grass fire that began when strong winds knocked down a utility pole at the U.S. Army's Pueblo Chemical Depot complex, said depot spokesman Charles Sprague.
No munitions at the complex were threatened, but at least 600 employees and construction workers were evacuated from a construction site and administration buildings as a precaution, Sprague said. The fire was 95 percent contained Thursday night.
The fire jumped the depot perimeter and burned a shed-like structure, Sprague said. No injuries were reported.
In Longmont, northwest of Denver, a small grass fire that started Wednesday morning east of U.S. 36 grew to 7 acres before it was contained. A fire scorched 300 acres of grass near La Junta in southeast Colorado before it was contained.
Associated Press writer Catherine Tsai contributed to this report.