The High Park fire, near Fort Collins, Colo., which has burned 68,200 acres, was 55 percent contained by Wednesday evening, after "the best day of firefighting in days," The Denver Post reported Thursday.
The Larimer County, Colo., Sheriff's Office said it had allowed residents in the Soldier Canyon, Mill Canyon Estates and Glacier View areas, on the perimeter of the fire, back to their homes Wednesday, but advised them to be ready to leave again if necessary.
"We're slowly trying to get people back as quickly as we can," said Sheriff's Office spokesman John Schulz.
"We are very encouraged by what we're doing on the fire," said firefighter spokesman Brett Haberstick.
A fire in Sevier County, Utah, that has affected more than 1,500 acres between the communities of Glenwood and Annabella, is considered 90 percent contained, Interagency Fire Center spokesman Jason Curry said.
The Salt Lake Tribune reported Thursday 75 firefighters, with a water-bearing helicopter and an air tanker dropping fire retardant, have battled the fire.
A fire burning through Ponderosa Pines in Arizona's Tonto National Forest has grown to more than 11,000 acres, and is considered 15 percent contained, the Arizona Republic reported Thursday. More than 700 firefighters are working to contain the blaze, which is threatening two power lines, the newspaper said.