Firefighters responded to a small brush fire near Julian Monday afternoon.
The nearest ground access was Farmers Road, according to Cal Fire officials.
Air units estimated the size of the fire to be approximately two acres with a moderate rate of spread.
Within an hour, the fire had grown to 15 acres according to a Cal Fire post on Twitter.
The forward rate of spread had stopped at 2:30 p.m. according to Cal Fire spokesperson.
It may take at least two hours to fully contain and mop up.
No structures in the area were threatened.
No word on cause.