A fierce wildfire that has destroyed more than a dozen homes and forced the evacuation of 1,500 residents raged largely unchecked in southwestern Utah for an 11th day, as an army of firefighters struggled to control the flames.

As of Tuesday (June 26) morning, the blaze had scorched nearly 50,000 acres, the bulk of that in the Dixie National Forest.

Crews managed to carve containment lines around just 10 percent of the fire’s perimeter, officials said.

The fire was caused by human activity, officials said. It erupted on June 17 near the ski resort of Brian Head, Utah, about 30 miles northeast of Zion National Park, and spread quickly as high winds drove flames into dense forests, threatening homes in nearby communities.

The Brian Head blaze ranks as the largest of 20 major, active wildfires burning across Utah and five other Western states – Arizona, California, New Mexico, Idaho and Oregon. Those fires have blackened a total of 150,000 acres, according to the National Interagency Fire Center in Boise, Idaho.

Another large blaze in Arizona dubbed the Frye Fire has charred nearly 40,000 acres since it was sparked by lightning on June 7 near Mount Graham, but it was more than 40 percent contained by Tuesday, authorities said.