The fire spans 17,305 acres in the San Bernardino National Forest, California officials said Sunday. The blaze -- which is 21% contained -- has already cost $5 million, according to NBC Los Angeles. About 500 structures have been listed as "threatened," according to officials, but none so far are believed to have been damaged or destroyed.
The cause of the 25-square-mile fire, which was first reported on June 17, remains under investigation. Nearly 2,000 firefighters and other responders are currently battling the blaze, according to NBC News.