Last Updated 12:16 p.m. ET
(CBS/AP) Authorities are ramping up the fight against large wildfires burning out of control in northern Colorado and southern New Mexico.
A wildfire burning in a mountainous area about 15 miles west of Fort Collins has nearly doubled to 58 square miles, forcing hundreds of evacuations and destroying at least 18 structures.
The Larimer County Sheriff's Office said Monday that 400 people are now fighting the blaze. The U.S. Forest Service says a federal team will take over management of the fire on Monday.
Ten air tankers, half of them large aircraft, were at a fire burning on nearly 60 square miles in a mountainous area about 15 miles west of Fort Collins on Monday. One person is unaccounted for the fire.
One firefighter was treated for minor injuries and released.
Meanwhile, strong winds 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."
Active Fire Mapping Program (USDA Forest Service)
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.
The High Park Fire has proven to be a tough adversary for firefighters. It has burned more than 20,000 acres and is spreading rapidly. Up to 2,600 people have been evacuated.
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.
Eight air tankers -- including two from Canada -- and several helicopters were on the scene to help fight the blaze, while hundreds of firefighters are on the ground.
"The unfortunate part is we've got dozens of engines up there but we've got hundreds of homes," said Sheriff Smith. "And as you get into some of those areas, we can't afford to get firefighters trapped in some of those far back areas."
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.
Sheriff Smith said the fire is creating its own weather - pushing and pulling the winds in every direction.
"We don't have a fire going in one direction that we can work with; we got it going multiple directions, so we have no containment goals at this time, merely get people out of the way," Sheriff Smith said.