Northwestern Pennsylvania’s Allegheny Islands Wilderness is, at just 372 acres, one of the country’s smallest wilderness areas. It’s nevertheless a fascinating and ecologically precious one. The wilderness, established in 1984 and managed by the U.S. Service, is located on seven islands scattered along a 56-mile stretch of the Allegheny River, between the Buckaloons Recreation Area and the town of Tionesta.
The islands of the Wilderness—Crull’s, Thompson’s, Baker, Courson, King, R. Thompson’s, and No-Name—were formed by the alluvial action of the Allegheny. Built of sand, mud, and clay originating in the Allegheny Mountains, they owe their size, shape, and changeable character to the river’s restless patterns of deposition and erosion.
At 96 acres, Crull’s Island is the largest in the Allegheny Islands Wilderness; No-Name, by contrast, is just 10 acres in size.
Major tributaries along this length of the Allegheny include Anders Run, Clark Run, Thompson Run, Tidioute Creek, East Hickory Creek, and Little Hickory Run.
The Allegheny Islands Wilderness preserves outstanding groves of old-growth bottomland forest, although ecosystems here are in multiple successional states due to the regular influence of flooding, storms, and other disturbance agents. Typical hardwoods include American sycamore, silver maple, green ash, slippery elm, shagbark hickory, butternut, hawthorn, and willows. Some of the trees are impressively large: Within the Wilderness is Pennsylvania’s (current) champion sycamore, a 148-foot-tall specimen.
Birdlife is prolific and varied within the Wilderness and adjoining portions of the river. Keep an eye peeled for great blue and green herons, kingfishers, turkey vultures, ospreys, bald eagles, and numerous varieties of waterfowl. The waters are important habitat for the Allegheny’s globally significant population of freshwater mussels.
This area was historically frequented by a number of American Indian cultures, particularly the Iroquoian Seneca. During the Revolutionary War, Thompson Island was the site of a fight between allied British/Iroquois forces and American soldiers under the command of Col. Daniel Brodhead.
No designated trails exist in the Wilderness, but the river-bottom woods are fairly easy to explore cross-country during early spring, before understory vegetation thickens. Canoeists and kayakers have much to explore: The portion of the Allegheny in the Wilderness belongs to an 87-mile “Recreational” stretch classified in the National Wild & Scenic Rivers System.
Leave No Trace
How to follow the seven standard Leave No Trace principles differs in different parts of the country (desert vs. Rocky Mountains). Click on any of the principles listed below to learn more about how they apply in the Allegheny Islands Wilderness.
Digital and paper maps are critical tools for wilderness visitors. Online maps can help you plan and prepare for your visit ahead of time. You can also carry digital maps with you on your GPS unit or other handheld GPS device. Having a paper map with you in the backcountry, as well as solid orienteering skills, however, ensures that you can still route-find in the event that your electronic device fails.
Motorized equipment and equipment used for mechanical transport is generally prohibited in all wilderness areas.
This includes the use of motor vehicles, motorboats, motorized equipment, bicycles, hang gliders, wagons, carts, portage wheels, and the landing of aircraft including helicopters.