The conditions there have been ripe for wildfire with hot temperatures, low humidity, gusty winds and dry vegetation, the park said, adding that weather will remain a concern Friday.
The Grand Canyon's North Rim in Arizona also closed Thursday because of a wildfire on adjacent Bureau of Land Management land near Jacob Lake. The Coconino County Sheriff's Office said it helped evacuate people from an area north of Jacob Lake and campers in the Kaibab National Forest nearby.
The fire began Wednesday evening after a thunderstorm moved through the area, fire officials said. It has burned about 1.5 square miles (3.9 square kilometers) with zero containment.