A fire in TImm Ranch in Okanogan County has spread to 500 acres. Emergency Management crews said the fire started after lightning sparked a brush fire in Okanogan County Wednesday afternoon. Officials said the 500 acre fire is burning in the Colville Reservation near Timm Ranch and Thunder Basin. Crews said the fire is burning in rugged land and there are no structures threatened. Mount Tolman fire center and Fire District 8 responded to the fire. The fire is 50 percent contained.