Colorado Gov. Jared Polis issued a disaster declaration on Sunday after lightning storms ignited multiple fires across the region.

More than 7,600 acres of Colorado’s Western Slope have been burned by four lightning-sparked wildfires, according to fire officials.

The South Rim Fire at the Black Canyon of the Gunnison National Park increased to 3,633 acres overnight and is zero percent contained, according to Bethany Urban with the Rocky Mountain Area Coordina...