The Trinity Ridge Fire was reported to be 17 percent contained Wednesday night.
Meanwhile, more than 1,300 firefighting personnel continue to fight the Elmore County blaze, which has burned nearly 140,000 acres.
Fire officials said the fire remains active in the Sheep Mountain area, growing further into Pete and Repeat Creek drainages. Ten helicopters are on the scene, using bucket drops to douse the most-active fire areas.
Meanwhile, a new fire was reported Tuesday night in the Boise National Forest. The New Zumwalt Fire is located two miles east of Highway 21 and four miles northwest of Grandjean. The blaze is 15 acres in size and has two crews along with two helicopters working to contain it.