The nearly 2,700-acre blaze, unstoppable in Wednesday's erratic wind south of Reno, was 75 percent contained in a light breeze Thursday.
``Cooler temperatures and higher humidity really helped us out last night,'' fire spokesman Franklin Pemberton said. ``It let us lay down more (containment) line. We're making some good progress.''
More than 500 firefighters, 14 tankers and seven helicopters were fighting the blaze.
At least 13 structures, including the six homes and seven outbuildings, had burned as the wind gusted to 35 mph, according to Reno Fire Marshal Larry Farr.
The blaze began when a bullet fired by a target shooter ricocheted off a rock. Farr said the man was shooting in a legal location. Officials said the man tried to put out the fire with dirt, but it spread too fast.
Five years of drought in the area has left grass, brush and light timber ready to explode.
No charges had been filed in similar incidents, but Farr said his office was working with the county district attorney's office to see if there was any illegal discharge of firearms.
