The Pilot Fire has burned more than 7,860 acres as of Wednesday. The fire is only 64% contained.
The blaze is in the San Bernardino National Forest north of Crestline near Silverwood Lake.
Over 5,300 structures are threatened and a mandatory evacuation has been issued for the Deer Lodge Park community.
Highway 173 is closed between State Route 138 and Arrowhead Lake Road and at North Bay Road. Other local roads are closed as well.
The fire started Sunday near Pilot Rock Conservation Camp.