forestland. how challenging is the terrain? extremely challenging. reporter: this is where trees are torching. we watched as the fire made a run up a canyon wall. it s a challenge to keep the fire from crossing the road edging closer to hundreds of homes. the steep, rugged terrain makes it too dangerous for people. that s why they have the helicopters. nine helicopters are part of the air attack dousing the flames with 2,000 gallons of water in each run. the elite, highly trained hot shot firefighters are on the ground watching the weather, especially the winds. it wasn t even a year ago a deadly yarnell fire claimed the lives of colleagues. back to the basics, be prepared. make sure there are escape routes and safety zones. they are evaluating them so they have a place to go.