A USA TODAY analysis found more than 600 fires that burned at least partly inside national parks in the past four decades.

The Dragon Bravo Fire, which had been about 20% contained, is now down to just 4% containment. What fueled the fire's sudden growth?

Historically dry conditions have combined with gusty winds to make it harder for crews to get a handle on a wildfire burning along the North Rim of the Grand Canyon, causing containment figures to plummet as the blaze nearly tripled in size in just a few days.