May 2 (UPI) -- More than 1,000 firefighters are working Monday to contain a blaze in New Mexico that's the largest active wildfire in the United States -- the Calf Canyon-Hermits Peak Fire, which is being driven by strong winds.
The fire in northeastern New Mexico began last month and has so far charred more than 116,000 acres, authorities said. It's a result of two fires close to each other that combined and is one of several wildfires burning in New Mexico and the western United States.
Officials have issued evacuations for thousands of residents who are in or near the fire's path, including a jail in the town of Las Vegas.
San Miguel and Mora counties issued evacuations late Sunday and cautioned that "refusing to leave could be a fatal decision."
"They told us that [late Sunday] and [Monday] will be the two worst days we've seen so far," Las Vegas City Councilor Barbara Perea Casey told the Albuquerque Journal.
Officials said there are plans to evacuate a nearby health institute, if necessary.
New Mexico Gov. Michelle Lujan-Grisham has activated the National Guard to help in fighting the fires and evacuations.
The wave of must-leave orders has swamped evacuation centers in both counties. The Santa Fe National Forest closed its Pecos and Las Vegas Ranger Districts around Las Vegas.
The blaze began on April 6 when a prescribed burn that intended to clear away a section of trees grew out of control. Officials say it's about 30% contained.
Warmer temperatures and strong winds were expected Monday, making the blaze more difficult to control.