One of the hikes we did on our 2017 river trip was to a place known as the "Silver Grotto" in Shinumo Wash. To reach this location, you must swim through not one, but two long pools of water. We float our camera gear in dry bags as we make the swim. The canyon walls are so tall that sunlight rarely makes it to the bottom of the canyon meaning the water is incredibly cold. For this reason, Silver Grotto is also known as "Shiver Grotto."