NOTE: If you've already dropped down from the alcove or are returning to the gym to pick up missed rewards, follow the initial steps for bronze #12 to reach the vertical bar mounted on the irregularly shaped rock wall. Then continue following the steps below.
Jump to the right to grab the horizontal crevice. Climb to the right and then jump to grab the movable ladder, which should still be flat against the wall. If necessary, climb up the ladder a bit. Then jump from the ladder to grab the lower horizontal crevice in the rock wall to the right. Climb to the right and jump up to grab the higher crevice.