Other structures and power lines were threatened, but no evacuations were ordered, said Larry Helmerick of the Rocky Mountain Area Coordination Center in Denver.
The fire started Thursday night and was burning mainly on private land east of the national monument. Lilly Park Road, which leads from Elk Springs on U.S. 40 to the east part of the monument, was closed.
The cause of the fire was under investigation. Elk Springs is 180 miles west of Denver and 170 miles east of Salt Lake City.
Four heavy air tankers, five fire engines, two water tenders and 20 firefighters were on the scene, and more personnel were on the way, Helmerick said.
Helmerick said all of western Colorado is under a ``red flag'' warning, indicating that conditions are dry and wildfires are a threat.
``When we have red flag with an ignition, that just means that we've got our hands full,'' he said.
Helmerick said the forecast in the Elk Springs area called for winds of 20 to 40 mph with low humidity.
Dry thunderstorms were also possible across Moffat County, but a cold front was expected Friday night.