Denver, Oct 21 (IANS): Raging wildfires in Colorado have prompted authorities at the Arapaho and Roosevelt National Forests to temporarily close all national forest land in five of the state's counties.

The affected counties are Larimer, Boulder, Clear Creek, Jefferson and Gilpin, The Coloradoan newspaper said in a report.

The closure, which started on Tuesday midnight, will be re-evaluated daily.

Last weekend, the Cameron Peak, CalWood and Lefthand Canyon wildfires grew significantly and were expected to further expand as firefighters continued to try and contain them amid hot and dry weather conditions.

Authorities closed 300,000 acres of the Roosevelt National Forest in the Canyon Lakes Ranger sistrict in Larimer county shortly after the Cameron Peak Fire started August 13 and on October 13 shut the entire district.

The Arapaho and Roosevelt National Forest spans 1.5 million acres.

"The number of large fires and extreme fire behavior we are seeing on our forests this year is historic," The Coloradoan quoted forest supervisor Monte Williams as saying in a statement on Tuesday.

"These temporary closures are necessary to protect the public and our firefighters, and we will keep them in place until conditions improve and we are confident that the risk of new fire starts has decreased."

As of Tuesday morning, nearly 442,000 acres have been scorched by the wildfires across north-central Colorado and southern Wyoming, according to the Rocky Mountain Coordination Center.