This is a really fun section where Rock Creek flows through a belt of Diabase rock near the Gettysburg Battlefield. The run begins slowly before entering a natural slalom through boulders. There are lots of turns and slots to maneuver through. Late in the run, the gradient increases and the rapids reach Class 3 in the finale above Rt. 97. This run can be combined with Middle Creek and Marsh Creek to make the Getttysburg Diabase Triple Crown! Rock has the shortest runable window of the three so starting with Rock is a good idea.