Colorado fire reveals ancient ruins

Mesa Verde National Park has been closed indefinitely

A brush fire which has closed a US national park, has uncovered some unknown ancient ruins.

Mesa Verde National Park in Colorado is the site of several native American cliff dwellings discovered by cowboys more than 100 years ago.

But a fire that has been raging since last Thursday has stripped away vegetation to reveal at least 10 new archaeological sites.

About 1,000 tourists have been evacuated from the park.

Risk of damage

"It's a bit of a trade off," said Jane Anderson, who is managing a £3m study into the park's cliff dwellings. "It's exciting to see the new ruins and get that information, but at the same time, fire can destroy these sites," she said.

"Sandstone explodes when it's heated."

By Sunday the fire had spread through 4,800 hectares (12,000 acres) to within 5km (three miles) of the Cliff Palace ruins, the park's major attraction.

It has reached Morefield Canyon where there are hundreds of known sites, but so far none of the cliff dwellings have been damaged.

Firefighters say only about 15% of the blaze, thought to have been started by lightning, has been contained.

Picturing the past

A dozen archaeologists have been working with more than 500 fire fighters to help identify new sites and protect them if possible.

"As more sites are added, it becomes clearer as to what happened," said archaeologist Larry Nordby.

"It allows us to get a snapshot at what the landscape looked like and we hope to expand that over the next several years."

Mesa Verde, which means 'Green Table' in Spanish, is the USA's largest archaeological area with more than 4,000 identified sites, nearly 400 of which were discovered after a 1996 fire.

The cliff dwellings and other structures were built when the ancestors of Pueblo Indians, or Anasazi, lived in the area between 550 and 1300 AD

The high temperatures and strong winds have also helped start fires in other parts of Colorado, southern California and Oregon.