More people were forced out of their homes this weekend outside the Idaho ski town of Ketchum and Sun Valley as a wildfire being strengthened by strong winds made a push to the north, threatening 10,000 residences, but fire managers are expressing optimism in their battle.

The blaze, which was started on Aug. 7 by lighting and has since grown to 158 square miles as of Sunday morning, is now 9 percent contained, the U.S. Forest Service told Fox News.

Beaver Creek Fire information officer Madonna Lengerich told Fox News that fewer winds and higher humidity kept the fire’s overnight growth to about a mile and a half, but stronger winds are in the forecast for Sunday.

The number of homes evacuated by the fire rose to more than 2,300 by Saturday evening. Another 7,700 in the area are under pre-evacuation, KTVB reports, as authorities are urging homeowners to start packing up their belongings if they are forced to leave. But despite the adverse conditions and extreme fire behavior, some progress was made on the Beaver Creek Fire’s south end, where crews conducted mop-up along the borders of blackened foothills west of Hailey.