Mandatory evacuation orders issued for Grand Canyon's North Rim as White Sage Fire burns 1,000 acres, with Highway 89A closed and officials warning of extreme heat.

Spreading wildfires forced the evacuation on Friday of part of the famed Grand Canyon, with the US National Park Service appealing for visitors to stay calm.

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.