The Tank Hollow Fire had blackened nearly 4,600 acres on Wednesday, but crews reported good progress in gradually hemming in the blaze that has been burning in Spanish Fork Canyon since Aug. 11.
The lightning-sparked blaze, about 20 miles east of the city of Spanish Fork and north of U.S. 6, was 32 percent contained as of mid-day Wednesday, according to the Interagency Fire Center.
Full containment was still a ways off, with a date of Oct. 15 projected.
Late Tuesday, the fire had spread northeast into Baker Canyon with gusty winds briefly forcing some crews to retreat.
On Wednesday, some 250 firefighters worked to cut a line from Sheep Creek Road to Water Hollow to protect power lines in the remote, rugged and steep terrain.
While working to keep the fire from spreading beyond the lines, crews were allowing the flames to continue to consume timber, brush and grass within its interior.
No homes or other structures have been lost or were threatened.