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.

U.S. land managers are racing the clock as hotter, drier weather raises the risk of wildfires in the nation’s overgrown forests with each passing year.

"The National Park Service and our interagency partners actively fought the Dragon Bravo fire employing tactics that met the suppression objectives and mitigated risk," Pawlitz said.