DENVER — Firefighters battling wildfires in the West were hoping a holiday of calmer winds and higher humidity would help efforts against scores of fires burning across the region, while keeping a nervous eye for fireworks and other hazards.
A wildfire in Wyoming grew to 137 square miles Wednesday in Medicine Bow National Forest, a sparsely populated area about halfway between Casper and Cheyenne. The fire was only 25 percent contained.
Firefighters said structures were burned but it was too soon to know how many.
In Colorado, firefighters in Colorado Springs were hoping to push toward full containment of the most destructive blaze in state history. That fire has burned 28 square miles, killed two and destroyed almost 350 homes. It was 80 percent contained Wednesday.
In both Colorado and Wyoming, holiday temperatures were expected to peak in the 90s, continuing a relative cool spell after record heat last week helped prompt tinder-dry conditions. Humidity was higher, too, giving firefighters hope for progress against the blazes.
Air Force tanker planes returned to the flight line for firefighting missions on Tuesday after a deadly weekend crash. C-130 planes were in the air Tuesday fighting a wildfire south of Laramie, Wyo., that grew to 14 square miles and has forced hundreds of people to evacuate their homes.
The forecast wasn't as kind in Montana, where a mammoth 380-square-mile in Custer National Forest was gobbling up pine, juniper and sage with help from gusty winds. The fire has burned 16 homes.
Firefighters gave the blaze "extreme" growth potential on Wednesday, with wind gusts up to 45 mph predicted. Temperatures were expected to reach the 100s.
As firefighting efforts continued, holiday fireworks were canceled across the region. Colorado officials were calling off holiday displays from Fort Collins to Colorado Springs, while law enforcement was warning of hefty fines for people caught violating personal fireworks bans across the region.
Residents in some parched areas were joining police. In one Colorado Springs neighborhood, a homemade sign read, "FAIR WARNING: Anyone using or allowing use of fireworks in this neighborhood will be dealt with harshly! And that doesn't mean just by the police!"
An investigation continued through the holiday on the cause of the deadly Colorado Springs fire. Eight agencies, led by the U.S. Forest Service, were investigating how the fire started, said Jeff Kramer, spokesman for the El Paso County Sheriff's Office.
"You're literally working that origin area down on your hands and knees," Paul Steensland, a retired U.S. Forest Service investigator, told The (Colorado Springs) Gazette.
The National Interagency Fire Center in Boise, Idaho, which coordinates wildfire-fighting efforts nationwide, said 45 large fires were burning Wednesday, including 36 fires in nine Western states. In Colorado alone, three fires have destroyed more than 600 homes and killed six residents.