Visitors and staff at two national parks in the U.S. West have been evacuted because of wildfires. Officials at Black Canyon of the Gunnison National Park in Colorado say the park closed Thursday morning after lightning sparked blazes on both rims.

Reaching 1,640 acres in size, the wildfires in Black Canyon of the Gunnison National Park continue to burn with no signs of containment after two lightning strikes sparked the blazes Thursday.

A park spokesperson said there was heavy lightning activity early Thursday morning and two fires were spotted burning inside the park’s boundary.