The 77-acre Cruces Fire of July 18 was caused accidentally by a northbound vehicle on Highway 1 north of the Highway 101 interchange, according to the Santa Barbara County Fire Department. Information Officer Capt. Dave Zaniboni said the precise cause was unknown, but roadside fires are commonly caused by sparks from dragged trailer chains or overheated mufflers and catalytic converters. West of Buellton two days later, the 110-acre Windmill Fire was caused by a tractor operating in an agricultural field near dry vegetation.