Shikellamy State Park is a 132-acre (53 ha) Pennsylvania state park located at the Confluence of the West Branch Susquehanna River and Susquehanna River in Pennsylvania in the United States. The park is divided into two sections. The older part, on a bluff on the western bank of the river, is the 78-acre (32 ha) Shikellamy overlook in Union Township, Union County. The newer part is the 54-acre (22 ha) marina on the southern end of Packer Island in Upper Augusta Township, Northumberland County. Packer's Island lies between the city of Sunbury and the borough of Northumberland at the confluence of the two branches of the river.
Shikellamy Overlook offers two scenic overlooks. They are 360 feet (110 m) above the confluence of the West Branch Susquehanna River and North Branch Susquehanna River. One can get a view of the northern and western rivers as well as a bird's-eye view of Northumberland, Sunbury, and Hummels Wharf.A breeding pair of state-endangered Peregrine Falcons have established a successful nest on The Cliffs below the scenic overlook. It is only the third known "wild nest" built by the birds in the state. Most other breeding pairs have been introduced to sites throughout the state by the Pennsylvania Game Commission.