The Whitewater-Baldy fire, the largest in New Mexico history, has grown an additional 20,000 acres since Wednesday to more than 190,000 acres, officials said.
The fire, which has burned a dozen homes, could grow to 230,000 acres before crews are able to contain it, which could take 10 days, KRQE-TV, Albuquerque, reported.
The Gila National Forest blaze -- which began as two separate fires, both caused by lightning -- was 5 percent contained, the Los Angeles Times reported.
Fire information officer Iris Estes cited rising relative humidity as a cause for relief.
"The humidity has risen up out of the single digits," she said Thursday. "Last night it rose to 38 percent. Hopefully, the trend will stay and help us out a bit."
New Mexico Gov. Susana Martinez flew over the fire Thursday afternoon.
Among concerns, Martinez said are "the size and the very difficult terrain and making sure we don't lose a firefighter or anyone fighting the fire because of the difficult terrain we're dealing with."
It has cost an estimated $9 million to fight the fire so far, KRQE said.
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