Central Arizona Fire and Medical responded to a wildfire this morning off Highway 169 outside of Dewey-Humbolt. Fire Marshal Rick Chase says crews arrived to find a ¼ acre fire burning in light grasses and quickly extinguished the blaze.Chase says the cause of the fire is undetermined but most likely caused by a spark from a vehicle or a discarded cigarette butt. Highway 169 was down to one lane while crews worked to extinguish the blaze.