Rapid growth on the South Rim fire in Black Canyon of the Gunnison National Park forced immediate evacuations in Montrose County on Saturday afternoon.

A wildfire that's burning in the southern part of Black Canyon of the Gunnison National Park has grown to more than 1,600 acres.

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.