TAOS, N.M.: The United States' largest active wildfire bore down on New Mexico mountain villages on Tuesday, triggering evacuations in another county as firefighters saw no way to stop the blaze.

Driven by gusting winds the fire reached a highway that is the only way out of the village of Chacon where some people have stayed to defend homes, according to Mora County Under Sheriff Americk Padilla. 

In nearby Angostura, ranchers and second-home owners were told to flee, marking the first evacuations in Taos County, which like the rest of the fire zone is caught in a more than two-decade-long drought.

Around 25 miles (40.23 km) north, tourists in the town of Taos took pictures of pyrocumulus clouds formed when air superheated by fire rises and then condenses.

The blaze has burned an area around the size of all five boroughs of New York City in a 42-mile-swath of the Sangre de Cristo mountains.

"There's no good place with the fire behavior and the wind we've been having to stop it anywhere in here, so we're going to have to protect all these homes as we go to the north," Todd Abel, a battalion chief with the National Wildfire Coordinating Group, told a briefing.

The fire is destroying ancestral forests and watersheds used by Indo-Hispano villages for centuries for building materials, firewood and to irrigate high mountain pastures.

The so-called Hermits Peak Calf Canyon blaze is one of around a dozen in the Southwest that started earlier this year as climate change dried out forests and caused stronger-than-normal spring winds, forest biologists say.

Hundreds of homes and other structures have been destroyed by the fire and about 12,000 households have been told to evacuate, with fears some centuries-old communities will never recover. 

The blaze started on April 4 when a controlled burn by the U.S. Forest Service got out of hand and then merged with another blaze to burn 203,920 acres (82,527 hectares). The cause of the second fire remains under investigation.

The eastern flank of the fire has been contained, allowing villagers on Tuesday to return to communities like Pendaries and Cañoncito that were the first to lose homes.