In Arizona, containment of the Tunnel Fire increased to 20% on Monday night, and the U.S. Forest Service in the Coconino National Forest said the blaze spanned 19,344 acres.
"The reduction in size is due to more accurately depicting the fire’s edge south of Darton Dome following the lava flows," the agency said.
Fox Weather reported that fire weather conditions there are expected to reach record-breaking levels for this time of year, with winds shifting southwest.
The Coconino County Sheriff’s Office said that an estimated 109 properties were affected by the fire, including 30 residences that were burned.
Arizona Gov. Doug Ducey declared a state of emergency for the county "to assist impacted communities with the resources needed to respond to and recover from the fire’s destruction."
Meanwhile, two New Mexico fires – the Calf Canyon Fire and Hermits Peak Fire – have merged, stretching a combined acreage of 60,173 acres, according to the U.S. Forest Service in the Santa Fe National Forest.
Evacuations in the northern part of the state remained in place for several communities on Monday.
Conditions there were still too volatile for authorities to assess the damage caused Friday and Saturday.
Members of New Mexico’s congressional delegation joined Gov. Michelle Lujan Grisham on a call Monday with officials from the White House and federal agencies to appeal for more federal ground resources.
The governor declared states of emergency in four counties last week.
In Nebraska, a southwestern prairie fire killed one person, injured at least 15 firefighters and destroyed at least six homes.
A retired Cambridge, Nebraska, fire chief who was helping as a fire spotter in Red Willow County died Friday night after his truck went off the road due to blinding smoke.
The body of John Trumble, 66, of Arapahoe, was recovered around early Saturday.
The Nebraska Emergency Management Agency said Tuesday that the Road 702 fire engulfed 41,448 acres and was 47% contained due to the work of nearly 160 firefighters.
Large fires have been reported around the country, including in Colorado, Florida, South Dakota and Texas.
The Gazette, a Colorado paper, reported last week that a northern Colorado Springs fire that forced the evacuation of 500 homes was caused by allegedly illegal construction work.
The National Interagency Fire Center said the amount of land singed to date is outpacing the 10-year average by about 30%.
Wildfire has become a year-round threat in the western U.S. Scientists have said that problems have been exacerbated by decades of fire suppression and poor management along with a more than 20-year megadrought that studies link to human-caused climate change.
The Associated Press contributed to this report.