Cross the road from the parking area at the top of the hill and follow this nice easy trail to a lovely viewing deck overlooking the Mississippi River and Sentinel Rock. You may even see rock climbers making their way up the rock face!
From the Sentinel Rock Viewpoint, you can return to the trailhead using the northern section of the loop for something different. There are more small rocks and roots, and it can be slippery when wet. There is more of a grade, as you descend a bit and then climb up again. There is also a connector that leads to the lower picnic area and shelter. The path is not as wide and there are some nettles and poison ivy, so long pants are recommended.