Accessible only by boat, the 50-acre Allegheny Islands State Park consists of two alluvial islands and seven shoals in the Allegheny River. The park is heavily covered in vegetation and remains undeveloped. Some of the few islands left in a natural state, the islands are homes to many animals and plants and frequently flood. The 14-acre upper island (eastern) is opposite the mouth of Black Run and east of C.W. Bill Young Lock and Dam #3. The 34-acre lower island (western) is west of the lock between the mouths of Falling Springs Run and Black Run.