MONUMENT, Colo. (AP/CBS4) – Firefighters gained the upper hand Saturday on a wildfire burning near the U.S. Air Force Academy.

The wildfire near Monument had burned about 60 acres in the foothills north of the Air Force Academy by Friday evening. The cause of the blaze wasn’t immediately known.

READ MORE: Karrar Noaman Al Khammasi Sentenced To 45 Years In Prison For Shooting Of Colorado Springs Police Officer Cem Duzel

By Saturday afternoon, no smoke plume was visible, according to The (Colorado Springs) Gazette.

Firefighters were aided Saturday by a plane and two helicopters that dropped water and retardant ahead of the flames.

More than 100 people were fighting the blaze in rocky and steep terrain. Firefighters were cutting fire lines to block the blaze’s advance and trying to use the natural rock formations to fortify their lines of defense, said Ralph Bellah, a U.S. Forest Service spokesman.

Wildfire Resources

READ MORE: Planned Parenthood Clinic Shooting Suspect Robert Dear Ruled Incompetent

– Visit’s Wildfire Resources section.

– Read recent Wildfire stories.

Wildfire Photo Galleries

– See images from the most destructive wildfire (Fourmile Fire) and largest wildfire (Hayman Fire) in Colorado history.

MORE NEWS: Denver To Replace 8th Avenue Bridge Over South Platte River

(TM and © Copyright 2011 CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2010 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)