The nearly 13,000-acre wildfire burning in eastern Utah crossed the Colorado border Monday night, joining four other fires already burning on the western slope, fire officials said.

The Deer Creek Fire, which started in eastern Utah and has already destroyed several structures, has crossed the state line into Colorado, state fire officials said.

Governor Jared Polis has declared an emergency in Montrose, Delta, and Mesa counties due to raging wildfires, including the South Rim Fire in Black Canyon of the Gunnison National Park, which has burned over 3,