A ferocious wildfire outside California's Yosemite Park is displaying "unprecedented" behavior, "moving extremely fast" and limiting the amount of time authorities have to warn area residents to evacuate, a state fire official said.

"The fire behavior that we're seeing on this incident is really unprecedented," Cal Fire Battalion Chief Jon Heggie said of the Oak Fire, which has exploded to more than 16,700 acres and destroyed at least seven structures. "It's moving extremely fast and the reaction time to get people out is limited because that fire is moving so fast."

At least 3,000 people have been forced to evacuate their homes due to the fire, per a news release from Gov. Gavin Newsom's office Saturday, since it began Friday in the foothills of the Sierra Nevada.

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