Firefighters battled to link containment lines on the fire 14 miles northwest Nucla on Sunday as dry thunderstorms pushed the blaze in a different direction.
``It had had been moving north, northeast... but the winds pushed it to the west,'' said fire information officer Maggie McCaffrey.
Fire managers planned for the wind shift but were worried about the fire spreading in the new area burned.
Hot weather was forecast for much of the state this week, increasing the fire danger for what has so far been a relatively mild fire season.
About 17,000 acres have been burned in 889 wildfires this summer. In 2002, the Hayman fire along the Front Range burned 138,000 acres alone.
The Nucla fire is believed to have been started by a lightning strike on Friday and increased from 3,800 acres on Saturday to 4,200 acres.
The blaze was about 10 percent contained. The cause is under investigation.
A heavy air tanker helped battle the blaze Sunday, along with 164 firefighters, five engines, two helicopters and four single engine tankers.
Several hundred head of cattle, about seven buildings, trailers and 10 outbuildings, such as sheds and haylofts used for ranching were threatened, but firefighters managed to rescue most of the cattle, said Carson Berglund of the Rocky Mountain Area Coordination Center.
Berglund said remote, rugged terrain hampered firefighters' efforts to build a defensive ring around the fire. Bulldozers were clearing lines around accessible buildings and firefighters were burning out fuel from the area.
The fire was burning on Bureau of Land Management and Forest Service land, not far from the Utah border. Berglund said $250,000 has been spent fighting the fire, down from an earlier estimate of $900,000.
Firefighters were also monitoring a 200-acre wildfire in the Black Mountain Wilderness Study area about 12 miles west of Meeker in Rio Blanco County.
