Residents who lived near the river bed were evacuated as a precautionary measure.
Fire crews had to use bike trails and other walking paths to make way for fire lines to put out the blaze.
According to fire Capt. Mitch Wesche, the fire was due to heavy vegetation in that area, which caused fires to keep flaring up.
Of the 200 firefighters who were accompanying water-dropping helicopters, two were injured.
The extent of their injuries has not been revealed, but they were transported to Riverside Community Hospital for treatment.
At least one power pole was devoured by the fire, temporarily disrupting power in the neighborhoods.
The cause of the fire is still unknown.
