devil's den was located at the extreme left of the iii corps line, manned by the large brigade (six regiments and two companies of sharpshooters, 2,200 men in all) of brigadier general j. h. hobart ward, in maj. gen. david b. birney's division. it was the southern end of houck's ridge, a modest elevation on the northwest side of plum run valley, made distinctive by piles of huge boulders. these boulders were not the direct avenue of approach used by the confederates. the 3rd arkansas and the 1st texas drove through rose woods and hit ward's line head-on. his troops had lacked the time or inclination to erect breastworks, and for over an hour both sides participated in a standup fight of unusual ferocity. in the first 30 minutes, the 20th indiana lost more than half of its men. its colonel, john wheeler, was killed and its lieutenant colonel wounded. the 86th new york also lost its commander. the commander of the 3rd arkansas fell wounded, one of 182 casualties in his regiment.