More than 1,200 firefighters are at the massive blaze near the Arizona border, which has destroyed a dozen cabins and eight outbuildings, fire information officer Iris Estes said.
Experts say persistent drought, climate change, and shifts in land use and firefighting strategies mean other Western states likely will see similar fires this season.
"We've been in a long drought cycle for the last 20 years, and conditions now are great for these type of fires," said Steve Pyne, author of Tending Fire. Coping with America's Wildland Fires and a life science professor at Arizona State University. "Everything is in line."
Agencies in New Mexico, Colorado, Arizona and other Western states are bracing for the worst. Many counties have established emergency telephone and e-mail notification systems to warn of wildfires, and most states have enlisted crews from nearby states to be ready when the big ones come.
"It's highly likely that these fires are going to get so big that states are going to need outside resources to fight them," said Jeremy Sullens, a wildland fire analyst at the National Interagency Fire Center.
According to the National Weather Service, a dry climate is expected to prolong drought conditions across the Great Basin and central Rockies during the fire season. Large portions of Nevada, Arizona, Utah, Colorado and New Mexico will remain under severe drought conditions.
"We're transitioning from La Nina to El Niño so we have no guidance to what's going to happen, like if we will get more rain or less rain," said Ed Polasko, a National Weather Service meteorologist.
And it's unclear what type of relief will come from monsoon season, which starts in mid-July, since experts say it's difficult to predict what areas in the West will benefit, Sullens said.
The two-week-old Gila forest fire is the largest wildfire burning in the country. Its size this week surpassed New Mexico's last record fire, a blaze last year that charred 156,593 acres and threatened the Los Alamos National Laboratory, the nation's premier nuclear facility.
Officials on Thursday closed the Gila Cliff Dwellings National Monument due to smoke generated from the fire. The National Park Service said the closure would remain in effect until conditions improved.
Estes said the blaze was 5 percent contained.