The Pioneer Fire, burning in rugged wilderness between Idaho City and Lowman, has so far burned some 64,350 acres, according to Boise National Forest officials.
Crews have the fire about 28 percent contained.
Cooler temperatures and mild winds gave firefighters the opportunity to strengthen existing containment lines and build new ones -- while the total fire grew by less than 1,000 acres Monday, Forest officials said.
Highway 21 between Lowman and Idaho City reopened to public travel at 9 a.m. Tuesday, and Boise County has lowered the evacuation notice for Lowman back to a Level 1.
The public is encouraged to drive with caution through the fire area because fire crews are still working along the highway.
Firefighters will take advantage of predicted cooler temperatures and light winds to continue building and strengthening containment lines around the fire today.
Crews began line construction northwest of Lowman near Scott Mountain Road/Forest Service Road 555, and completed dozer and hand line west of Hole in the Wall Canyon north to the South Fork Payette River in an effort to box in the active fire burning west of Lowman that is threatening the Highway 17 corridor.
Firefighters successfully contained a small start north of Lowman called the Ridge Fire. The Idaho Transportation Department cleared hazard trees along Highway 21 from Idaho City to Lowman.
Forest officials say crews will look for opportunities to begin burnout operations along dozer lines west of Hole in the Wall Canyon down to the South Fork Payette River, and they will continue constructing dozer and hand line in the Deadwood drainage near Slaughterhouse Creek north of Highway 17, in an effort to protect Lowman and keep the fire from moving north.