LAPORTE, Colo. (AP) -- An eerie orange dusk shrouded part of northern Colorado, while heavy smoke choked a small community in southern New Mexico -- as both regions battled wildfires spreading rapidly through mountainous forest land that have forced hundreds of evacuations and destroyed dozens of structures.
The Colorado fire, burning in a mountainous area about 15 miles west of Fort Collins, grew to more than 31 square miles within about a day of being reported and has destroyed or damaged 18 structures.
The fire on Sunday sent up heavy smoke, obscuring the sun in the middle of the day. The smell of smoke drifted into the Denver area and smoke spread as far away as central Nebraska, western Kansas and Texas.
Strong winds, meanwhile, grounded aircraft fighting a 40-square-mile wildfire near the mountain community of Ruidoso in southern New Mexico. Crews were working to build a fire line around the blaze, which started Friday and has damaged or destroyed 36 structures.
It wasn't immediately clear how many of the structures lost were homes. "We're still trying to take a tally," Kerry Gladden, public information officer for Ruidoso, said late Sunday afternoon.
Dan Ware, a spokesman for the New Mexico State Forestry Division, said the number of Ruidoso evacuees was in the hundreds, but he didn't have an exact figure.
Karen Takai, a spokeswoman for the Ruidoso fire crews, said smoke is heavily impacting the community of Capitan, about 5 miles to the northeast. She said Capitan and others could also face evacuation.
"Any communities around this fire have the potential of being evacuated," she said. "If I lived in Capitan, I definitely would be prepared. Don't wait until the sheriff's office comes knocking at your door and tells you to evacuate."
Both fires were dwarfed by the Whitewater-Baldy blaze in southwest New Mexico -- the largest in the state's history -- that has charred 450 square miles of wilderness forest since mid-May. But the smaller blazes were especially concerning because they started much closer to more populated areas.
Elsewhere Sunday, firefighters were battling a wildfire that blackened 6 square miles in Wyoming's Guernsey State Park and forced the evacuation of between 500 and 1,000 campers and visitors. Cooler weather was helping firefighters in their battle against two other wildfires in southern Utah.
In Colorado, authorities sent nearly 1,800 evacuation notices to phone numbers but it wasn't clear how many residents had to leave. About 500 people had checked in at Red Cross shelters. Larimer County Sheriff Justin Smith said there was an unconfirmed report of a person unaccounted for, but he wouldn't elaborate.
Authorities say it's the worst fire seen in Larimer County in about 25 years. It spread as fast as 1 1/2 miles an hour Saturday, skipping over some areas but burning intensely in trees in others. Flames were coming dangerously close to deputies who were telling some residents to evacuate, Smith said.
Kathie Walter and her husband helped friends several miles away evacuate from the Colorado fire on Saturday. When they got home, they were surprised to get a call warning them to be ready to evacuate just in case. But Walter didn't want to wait.
"Smoke was coming in hard. We could not see flames or orange or black smoke. But we didn't need to see anymore. We just said `Hey, let's get out of here,"' she said.
They evacuated with their five cats and two dogs. They had a head start. After a wildfire in the area last year, they had left two suitcases packed in their garage.
Elaine Mantle and her family got a call to evacuate their Bellvue home at 5:45 a.m. Sunday. It took about 30 minutes for them to get out and reach a spillover shelter at the Budweiser Event Center in Loveland. Evacuees gathered there for a fire briefing, sipping coffee and eating bananas and powdered doughnuts, in a large gymnasium-like space.
It was the Mantles' first evacuation in the 25 years that they have lived in the mountains, and they were grateful to be safe.
"We're all here, we're all OK. Our neighbors are all here. We feel good," Mantle said.
The blaze also forced the evacuation of 11 wolves from a sanctuary near the fire. KUSA-TV in Denver reported that 19 wolves remained behind at the sanctuary, which has underground concrete bunkers known as "fire dens" that can be used by the animals.
The fire is the latest to hit Colorado's drought-stricken Front Range. In May, a fire set by a camper's stove charred 12 square miles in the same Poudre Canyon area. In March, a fire sparked by a prescribed burn 25 miles southwest of Denver killed three people and damaged or destroyed more than two dozen homes.
Eight air tankers -- including two from Canada -- and several helicopters were on the scene to help fight the blaze.
Authorities say they're competing for resources that have been diluted by several wildfires burning across the West.
"Resources are thin right now," said Nick Christensen of the Larimer County Sheriff's Office. "We are trying to get more of everything at this point."
Meanwhile, the speed at which the fire has spread has dashed any hopes of containment for the time being.
"These folks are doing everything they can, but Mother Nature is running this fire," Smith, the sheriff, said.
Associated Press writers Thomas Peipert in Denver and Amanda Lee Myers in Phoenix contributed to this report.