BLACK FOREST, the United States -- With thousands of evacuations and dozens of homes burning to the ground, fire fighters on Wednesday rushed to contain several large forest fires across the US state of Colorado's eastern foothills.

One fire in southern Colorado threatened the Royal Gorge national landmark - the highest suspension bridge in the US - and caused the evacuation of 900 prisoners at the nearby Colorado Territorial Correctional Facility.

Schad Dohl watches a wall of fire as it rages through Black Forest, Colorado June 12, 2013. [Photo/Agencies]

Another fire in the Black Forest near Colorado Springs has " eclipsed 80 and taken near 100 homes", El Paso County Sheriff Terry Maketa told reporters Wednesday.

"The smoke was so thick you couldn't see the road," Maketa said, citing one fire engulfed within one day close to 8,000 acres, including a number of million-dollar dwellings, and was "zero percent" contained.

Maketa compared the blaze to last year's devastating Waldo Canyon fire that razed 350 homes and promoted a visit from President Barack Obama who declared the scene a "National Disaster Area".

The El Paso County sheriff was also worried about loss of life, which may take days to determine. "We had people refuse to leave .. .I know we had people stay," he said, adding "We could be facing more tragedies."

More than 2,300 mandatory evacuations were ordered in Black Forest, and the fire will affect 7,358 people, Maketa said, noting the National Guard was bringing heavy aircraft by noon Wednesday to drop large quantities of water on the fire.

"Extremely dry conditions and record temperatures" have offset a record April snowfall in Colorado's Rocky Mountains and created optimal fire conditions, Jennifer Smith, spokesperson for National Interagency Fire Center in Boise, Idaho, said Wednesday.

According to Smith, in the past 12 days, nine large forest fires have broken out in Colorado and New Mexico, its neighbor to the south.

As of Wednesday, a number of fires were still raging in New Mexico, including the Thompson Ridge Fire (21,900 acres), the Silver Fire (8,400 acres); the Jaroso Fire (6,000 acres) and the Tres Lagunas fire (10,237 acres).

A total of five separate major fires sprung up in Colorado this week, stretching from Big Meadows, a 400-acre blaze in Rocky Mountain National Park, to 200 miles south at the Royal Gorge fire, where 3,800 acres were up in smoke.

The Royal Gorge Bridge and Park is a popular tourist destination and features a 1,260 ft (380 m) bridge suspended 1,053 feet above a canyon and the Arkansas River that dates back to 1929. The park has been closed since Tuesday and park officials confirmed at least 3 major structures on the property have been burned.

"Tomorrow we've got another red flag day ... high temperatures and potential winds," said Woody Percival, Royal Gorge public information officer. "It could get worse, although the bridge is safe," he noted.

The cause of the fires is currently under investigation.