Pennsylvania, United States
Hawk Mountain is a mountain ridge, part of the Appalachian Mountains, located in central-eastern Pennsylvania near Reading and Allentown. It is a part of the Blue Mountain Ridge. It is primarily known as home to the Hawk Mountain Sanctuary.
The River of Rocks is visible and accessible from the Sanctuary. The boulders were formed by periglacial processes in the Pleistocene epoch, or "ice age."