Explore one of Maryland's healthiest stream systems. Originating from the southwestern mountains of Pennsylvania, Sideling Hill Creek winds its way among the steep, forested, shale cliffs of western Maryland before it finally spills into the Potomac River. The Nature Conservancy's 700-acre Sideling Hill Creek Preserve has several trails so visitors can explore the variety of species and natural communites that exist in this area. Free admission. Access preserve map and downloadable audio tour on our website.