Sentinel Rock, North Face Direct. On May 7, late on the third day of climbing, Tom Frost and I completed a new route on the north face of Sentinel Rock. The standard route goes up near the right margin of the face, while our direct route ascends in a nearly straight line just left of the center of the face. Pitons and carabiners were fixed on the first pitch two days prior to the three-day successful effort, but even with this help we climbed only 350 feet on the first day. We were slowed principally by an overhang at the top of a 300-foot recess. The leader spent many hours here; a 25-foot fall and three pulled pitons bear testimony to the stubbornness of the overhang in yielding passage to a climber. We passed the night on a narrow ledge 50 feet higher. The highlight of the climbing next day was Tom’s lead of a peculiar line of ceilings 700 feet up. We bivouacked slightly higher. On the third day we climbed a pitch which involved, besides some interesting piton work, the use of three successive direct-aid slings on horns seven feet apart. We reached the summit at 4:30 p.m. The climbing had been almost all nailing, often using rotten cracks. We placed 203 pitons, all removed, and no bolts. This route appears to be in the class of the northwest face of Half Dome.