Firefighters were battling a 20-acre blaze in rugged terrain in the San Isabel National Forest Thursday afternoon, trying to contain the fire before it threatened ranches in the area.
The fire was reported Wednesday night in Custer County, about three miles southeast of Wetmore and 100 miles south of Denver.
The cause was unknown, said Larry Helmerick, a spokesman for the Rocky Mountain Area Coordination Center.
Two heavy air tankers and two single-engine air tankers were helping firefighters on the ground, and two hotshot crews were en route.
''Nothing is threatened, but we're concerned that if the fire does get off the mountain, it could impact some ranches,'' Helmerick said.
A 1,000-acre wildfire burning since June 23 about 10 miles southeast of Pagosa Springs in Archuleta County was being managed for ecological restoration.
