Investigators said Wednesday that an abandoned campfire sparked a fire 10 miles east of La Pine that burned 82 acres before crews could encircle it, one of two fires that broke out amid Tuesday's gusty winds on the High Desert.
Four hours later, another human-caused wildfire sparked near Highway 97 about 11 miles north of Madras, shutting the highway for close to three hours.
The Finley Fire, near the southwest part of the Newberry National Volcanic Monument, grew to 82 acres after burnout operations and more accurate mapping, officials said, and was 10 percent contained by Wednesday afternoon.
The Finley Fire southwest of Paulina Lake was fully lined by Wednesday morning, said Valerie Reed at the Central Oregon Interagency Dispatch Center in Prineville.
Meanwhile, a fire that broke out later in the afternoon and shut Highway 97 north of Madras for three hours had burned 1,018 acres by Wednesday morning and was 50 percent contained.
"This fuel model -- when you get wind on it, it will take off at about 20, 30 miles per hour, " said Jefferson County Fire Chief Brian Huff.
Sheriff's Det. Starla Green said they had a line around the fire perimeter but were working to reinforce it. More than 60 firefighters from several agencies battled the flames Tuesday night, with about 20 still on scene Wednesday.
"We're going to be doing a burnout operation so it doesn't jump into this unburned area, and then just mopping up along the edges," Huff said.
ODOT at midday made use of pilot cars in the area as crews began back-burn work near the highway.
A passenger in a car driving through the area Wednesday said, "It's pretty scary for sure, and it's too bad, because there's a lot of recreation area back in here."
Motorists were urged to drive with caution until the work was wrapped up and the highway fully open again by about 2 p.m., the agency reported.
Tuesday afternoon, the fast-moving fire forced ODOT to close a 7-mile stretch of the highway for close to three hours.
Green said one family living east of the highway was evacuated and notifications were given at four other homes to be ready to go, but they were not forced to leave and the one family returned home Tuesday night.
Jefferson County Fire District, U.S. Forest Service and BLM firefighters were called in the fight the flames, along with Warm Springs Fire and Safety and Crooked River Ranch crews, Green said.