LAS VEGAS — A massive mountain wildfire that made Las Vegas smell like a campfire destroyed six structures at a desert ranch and left two of the more than a thousand firefighting staff members with minor injuries, officials said Wednesday.

It wasn’t immediately clear if any homes were destroyed on the ranch several miles from woodsy Mount Charleston hamlets where crews were protecting more than 400 homes, a canyon hotel and a scenic alpine lodge and cabins.

One of the buildings that burned in the Carpenter 1 fire was a commercial structure at Prospect Springs, U.S. Forest Service spokeswoman Suzanne Shelp said.

More than 270 additional firefighters arrived Tuesday to help battle the fire sparked by lightning July 1, bringing to 1,077 the number of people fighting the blaze about 25 miles northwest of downtown Las Vegas. One firefighter injured a knee on Tuesday and another camp support staff member suffered heat illness, Shelp said.

Crews set backfires, cleared undergrowth and positioned more than 50 fire engines to protect homes in the Rainbow, Echo and Old Town areas in Kyle Canyon. But the fire grew about 9 square miles and overall containment dropped from 15 percent to 10 percent as erratic gusts of wind pushed flames up canyons, down the mountain and across state Route 157.

The main highway in and out of the evacuated Kyle Canyon area was briefly cut off, but crews bulldozed a fire line to protect the road, Shelp said. No homes in the canyon burned.

Overnight mapping put the fire at 25,524 acres, or almost 40 square miles, Shelp said.

“The big factor today will be what the wind will do, because we’re still hot and dry,” she said Wednesday.

The Federal Emergency Management Agency has promised to reimburse Nevada for 75 percent of the cost of the fire, which was growing by more than $1 million a day. Fire officials said late Tuesday the amount topped $6.2 million.

The wildfire near Las Vegas is the top firefighting priority in the West, fire officials said.

Wildfire roundup

Arizona

Residents were allowed to return Tuesday to about 100 of the 200 homes evacuated due to a wildfire in Kearny, located 73 miles southeast of Phoenix. Officials reported 5 percent containment of the fire after it burned about 300 acres of dense vegetation and one house since it was sparked by lightning on Monday.

Northern California

More than 800 firefighters battled a fire in the El Dorado National Forest west of South Lake Tahoe that spread to almost 1 square mile but was about 80 percent contained. A shed and an outhouse burned, but no homes were threatened by the fire that may have been sparked Monday by a broken axle from a motorhome towing a truck. All lanes along Highway 50 reopened Tuesday.

Southern California

Cooler and calm weather helped slow an 11-square-mile wildfire that destroyed at least 100 buildings at a mountain camp near Julian, 60 miles east of San Diego. The blaze was 40 percent contained Wednesday, and state fire spokesman Mike Mohler said a chance of thunderstorms later in the day could wet down hot spots. Evacuation orders remained in effect for 120 buildings, mostly empty vacation cabins, and campgrounds in the Cleveland National Forest remained closed.

Southern Colorado

The East Peak Fire was declared 100 percent contained Tuesday. The lightning-sparked fire burned 13 homes.