The size of the fire is roughly 28 square miles.
The fast-moving fire forced more than 82,000 residents of San Bernardino County to evacuate, a Cal Fire spokesman said.
Fire authorities warned of "imminent threat to public safety" as 0% of the fire had been contained as of Tuesday night.
The massive fire, which is being called Blue Cut, prompted Gov. Jerry Brown to declare a state of emergency in the area.