Sycamore Island

Sycamore Island Beach, Blawnox, PA 15238

Directions View Trail Map


The island is accessible by boat only. Before you go…

  • Check the weather. Wear a wetsuit if the water is below 60 degrees.
  • Check water conditions.
  • Remain on trails to avoid poison ivy.
  • Always wear a PFD while traveling to the island.
  • Leave no trace of your visit, ALT maintains public access as long as all visitors do their part to maintain and leave no trace.
  • Camping: An ALT camping permit is required. Inquire about availability and submit your completed permit to our Stewardship Team at, availability is on a first come first serve basis. Summer weekends fill up quickly.


Allegheny Land Trust acquired Sycamore Island in January 2008. Before the island was protected by ALT, the island had periodic interludes of recognition and appreciation by humans as a natural refuge. In 1936, both Sycamore Island and Nine Mile Island were leased from the Pennsylvania Railroad by the Audubon Society of Western Pennsylvania, making these islands the first bird sanctuaries in the Pittsburgh region. The Harbor Isle Boat Club was in existence on the island during the late 1960s, but were later abandoned leaving behind several significant features; including a barge that remains embedded in the sand at the island’s southern tip, a partially installed swimming pool, docking platform, and a series of offshore pilings in the back channel.

During the last century, development and industrialization of the watershed contributed to changes in the island’s configuration and topography, due in part to dredge spoiling and increased sedimentation from development. Because of these changes and the island’s position in the river, its area has more than doubled from just over 6 acres in 1809 to over 14 acres today. More recent impacts to the Island’s ecology include the effects of invasive species and climate change. All of these stressors must be considered and addressed in long-term management efforts.

The Pennsylvania Natural Diversity Inventory (PNDI) classifies floodplain forest as imperiled in the state, and Sycamore Island has a ranking of “high significance” within the Allegheny River Biological Diversity Area (BDA) Natural Heritage Area. The ecological and cultural significance of Sycamore Island is well known. Previous studies such as the 3 Rivers 2nd Nature Report conducted by Carnegie Mellon University characterizing riverbank vegetation in the Allegheny and Monongahela Rivers have described the ecological resources and conservation value of Sycamore Island (3Rivers 2nd Nature, 2002).

Sycamore Island's

Record Observations with iNaturalist