Two wildfires in western Colorado have burned more than 5,800 acres and continue to prompt mandatory evacuations, fire officials said Sunday morning.

Visitors and staff at two national parks in the U.S. West have been evacuated because of wildfires.

The combination of high temperatures, gusty winds, and dry vegetation has created dangerous conditions, fuelling the fire's swift advance, park officials said.

The Dragon Bravo Fire in the North Rim of the Grand Canyon "exhibited extreme and volatile fire behavior" overnight and expanded to about 5,000 acres, fire managers said Sunday.

A historic lodge on the Grand Canyon's North Rim has been destroyed by a fast-moving wildfire, the park said Sunday.

The park initially was managing it as a controlled burn but then shifted to suppression as it rapidly grew to 7.8 square miles (20 square kilometers) because of hot temperatures, low humidity and win...