Harriman State Park, State nature park in Orange County, United States.

Harriman State Park is a nature reserve in Orange County, New York, covering roughly 73 square miles (190 square kilometers) of mixed hardwood forest and rocky ridges. The terrain consists of rolling hills and narrow valleys filled with streams, wetlands, and small bodies of water scattered throughout the reserve.

Mary Harriman Rumsey and her mother donated several thousand acres from the family estate to New York State in 1910 to establish the park. Additional parcels joined the original donation over the following decades, and the Civilian Conservation Corps built trails and facilities during the economic depression of the 1930s.

The Appalachian Trail passes through the park for 19 miles, connecting hikers to a larger network of paths across the eastern United States.

Hiking routes range from short walks to full-day treks through woodland and along shorelines. Several lakes allow swimming and paddling, and most areas can be reached by car or on foot via marked paths.

A section of the Appalachian Trail crosses the reserve, linking walkers to a long-distance route from Georgia to Maine. Stone walls and old farm foundations lie scattered in the woods, reminders of settlements that existed before the reserve was created.