Updated

Authorities in central Idaho on Thursday asked Valley County residents living in homes or condominiums at the Tamarack Resort to clear out as firefighters battle the wind-fanned flames of a nearby wildfire fire.

An immediate evacuation was ordered earlier Thursday for subdivisions near the golf and ski resort.

But hours later, deputies began making the rounds to the pricier properties at the resort, located in the mountains west of Donnelly. Officials have also started warning residents farther away from the fire threat to be ready to leave at a moment's notice if strong winds forecast for the region help the 550-acre fire expand.

"Some people have been told they need to leave right now," said Madonna Lengerich, spokeswoman for the Bureau of Land Management. "Others are being told to be ready."

The Hurd Creek Fire began Saturday in a lightning strike but — fueled by wind gusts, dry conditions and heat — grew Wednesday night. More than 700 firefighters and support staff are on the scene and worked to contain at least 20 percent of it.

The blaze is one of three significant fires being fought across the state in a late-season surge in wildfire activity.

The Long Butte Fire burning in the southern Idaho desert is 50 percent contained. After revising earlier estimates, fire officials said the Long Butte blaze has now scorched more than 478 square miles of flat landscape populated by sagebrush and cheatgrass.

Some of the 306,000 acres that have burned since Saturday include the home range of a wild horse herd and about 75 percent of the Hagerman Fossil Beds National Monument. Officials said they managed to remove valuable fossil collections but are worried about the long-term impacts of the fire on fossil beds and active dig sites from erosion and mud slides.

Near the central Idaho town of Stanley, more than 560 firefighters are battling the Banner Fire, which grew by 350 acres Wednesday and has now scorched more than 2,000 acres.

But fire managers said gaining ground may be a challenge considering the weather predicted for southern Idaho Thursday. The National Weather Service has issued a red flag warning indicating extreme burning conditions and forecasts of a strong cold front moving into the southern portion of the state, bringing high winds and thunderstorms.

"At the moment we're OK," said Lengerich. "But by early this afternoon, it's supposed to get ugly."

In Montana, high winds also caused a prescribed burn to leave its boundaries in the Helena National Forest and be declared a wildfire, which prompted authorities to evacuate homes along Stemple Pass Road. Stemple Pass is northwest of Helena and a column of smoke could be seen from town.