Fire managers on the Coconino National Forest this week are continuing three pile burns near Flagstaff. The work began today and includes woody debris and material leftover from previous forest thinning treatments. Forest officials say the snow on the ground will give firefighters greater control of the projects. Crews planned to ignite about 100 acres near Interstate 17 south of Mountainaire, along with a pile burn north of Baderville and another off Schultz Pass Road. The work is expected to produce visible smoke in Doney Park and I-17 near Kelly Canyon, but should be light and short in duration.