Heavy winds that swept through Black Canyon of the Gunnison National Park on Sunday night started “rapid fire spread” after a relatively slow day of growth, according to fire officials.

Park officials have closed access for the season to the North Rim, a less popular area of the park that draws only about 10% of the Grand Canyon's millions of annual visitors.

The visitor center and a wastewater treatment plant were among the 50 to 80 structures lost, the park superintendent said. The area was evacuated Thursday.