Rappel Route is one of the better climbs at Main Rock, and doubles as the usual descent from the top of the rock. Face climb to a small stance below a bulge. Above the bulge is a blank face with a flake on the left side. I tried to climb through the bulge on some marginal, sloping holds, but ended up traversing to the right a little. Continue up the face above (thin, 5.9) or the flake to the left (5.8). Once above the face, the climbing eases significantly to the top.
The easiest way to access the Rappel Route is from the top of Main Rock. After climbing the Access Route, look to the right for a rock bridge with slings around it. Rap from the rock bridge (back up the old slings) to the base of the Rappel Route. At ground level, the start is to the right of the large buttress that splits the east face.