Skinbark lived on the mountain slopes west of Isengard. Saruman's orcs ravaged this area, cutting down trees and killing ents. Skinbark was wounded by the orcs and he retreated far up the mountain slopes to live among the birches that he favored. He refused to come down. He took part in the Battle of Isengard, and is seen smacking away dozens of orcs on the ground with a big stone.