Size: 372 acres
Year Designated: 1984
Fast Fact: The Allegheny Islands Wilderness is home to the federally endangered clubshell mussel and the Northern riffleshell.
Within Pennsylvania’s Allegheny River, which stretches for nearly 325 miles, lie seven islands which have been federally designated as wilderness: the Allegheny Islands Wilderness. Among the seven islands, old river-bottom trees, like willow, sycamore and silver maple, dominate the landscape. The islands were formed by deposits of sand, mud and clay carried downstream from the Allegheny Mountains.
The wilderness area (located in Allegheny National Forest) supports two small populations of endangered marine animals—the clubshell mussel and the Northern riffleshell, which are both federally and state-listed as endangered. Bald eagles also live in the area, as well as otters, osprey and blue heron.