PORTLAND, Ore. (AP) -- A layer of warm air has lifted over a fire on the north side of Mount Hood, allowing oxygen to rush into the blaze and sending smoke into towns nearby.
The Dollar Lake fire was still within its perimeter on Saturday afternoon, three miles from the Bull Run Watershed, which supplies 900,000 people in Portland with water. The fire began on Aug. 27.
Officials have said no structures are in imminent danger.
The layer of warm air, called an inversion, was trapping cool, smoky air close to the ground. It lifted at about 1 p.m. on Saturday.
Firefighters continued holding actions on the west flank of the fire while conducting mop-up duty on the south, north and east flanks.
The fire is burning about 16 miles south of Hood River.