(Adds disaster declarations from governor, paragraph 8)
By Keith Coffman
COLORADO SPRINGS, Colo., June 12 (Reuters) - A fierce, wind-whipped wildfire destroyed more than 90 homes and menaced additional communities in and around Colorado's second-largest city on Wednesday, forcing thousands of residents to flee.
The fast-moving fire raged out of control for a second day through heavily wooded rolling hillsides on the northeastern outskirts of Colorado Springs, devouring more houses into the evening as winds sent flames doubling back into areas already burned, authorities said.
"Properties that we identified as standing are now engulfed in flames so the numbers are changing as we speak," El Paso County Sheriff Terry Maketa told a news conference.
Jeff Stemas, 44, who fled with his wife, three dogs, a file cabinet and a computer as flames neared their house on Tuesday, learned on Wednesday from a website set up to track property losses that their home was among those destroyed.
"It's a total loss," he said with quiet resignation, shrugging his shoulders. "But I expected it."
The Black Forest blaze, named for the community near where it began, prompted authorities to order more than 7,000 people from their homes, while a separate, smaller fire about 50 miles (80 km) to the southwest forced the evacuation of 900 inmates from a state prison.
No injuries were reported in either fire. Investigators were seeking the cause of both blazes, which started Tuesday and underscored concerns that persistent drought could intensify this year's fire season in the western United States.
Governor John Hickenlooper signed executive orders on Wednesday declaring "disaster emergencies" that set aside more than $10 million for costs related to those two fires and a third, smaller blaze about 90 miles (145 km) south of Colorado Springs.
By evening, the Black Forest fire had charred an estimated 8,500 acres (3,440 hectares) and was expected to scorch at least a further 3,000 acres (1,215 hectares), defying efforts by some 500 firefighters to contain it.
"It's a very hot, very active, difficult fire," El Paso County spokesman Dave Rose said.
TOWERS OF SMOKE AND FLAMES
Towering plumes of black, gray and white smoke billowed above a fire line that stretched for miles as air tankers and helicopters made repeated passes over the blaze, dropping fire retardant and water. The blaze was especially intense at its northern flank, where leaping flames engulfed trees.
On Wednesday evening, police issued a voluntary evacuation alert, advising residents to be prepared to flee at a moment's notice, for homes in the northern end of Colorado Springs itself, in an area that lies east of the U.S. Air Force Academy.
It was barely a year ago that Colorado Springs, which lies at the eastern foothills of the Rockies about 45 miles south of the state's capital and largest city, Denver, had its last major brush with wildfire.
The most destructive blaze in Colorado history gutted more than 300 homes on the western edge of the city last summer, killing an elderly couple and forcing the evacuation of some 35,000 people.
The separate fire southwest of Colorado Springs forced the closure of one of the state's leading tourist attractions, the Royal Gorge Bridge, and the overnight evacuation of more than 905 inmates from the Colorado Territorial Correctional Facility in Canon City to other prisons.
The quarter-mile-long, 1,000-foot-high (300=metre) bridge, which spans the Arkansas River and is billed as the world's highest suspension bridge, was scorched by flames on Wednesday but remained intact, though 20 other structures in the area were lost, a fire official said.
Authorities put the size of the Royal Gorge blaze at 3,800 acres (1,540 hectares) on Wednesday.
Maketa said 92 homes in a subdivision northeast of Colorado Springs were listed as total losses from the Black Forest blaze and five more were damaged. Local television footage showed some homes in the area reduced to ashes.
Evacuation notices went out earlier to 2,600 homes, comprising an estimated 7,300 people, and Army National Guard troops were deployed to help police prevent looting.
The fires came as the U.S. Drought Monitor reported that 42 percent of Colorado was experiencing exceptional or extreme drought conditions.
The National Weather Service said single-digit humidity values and temperatures in the upper 90s Fahrenheit (upper 30s C), combined with wind gusts in excess of 40 miles per hour (65 kph) have created "very high to extreme fire danger" in Colorado for most of the week. (Additional reporting by Colleen Jenkins and Laura Zuckerman; Writing by Alex Dobuzinskis; Editing by Cynthia Johnston, Bill Trott and Peter Cooney)