4. Brother Island
This island lies just west of the Third Sister and downcurrent from it. The vegetation here is dense and lush, heavily wooded and apparently relatively unaltered. A narrow channel separates this island from the heavily trafficked Third Sister. This channel appears to be deep enough to prevent trespass, although the bottom is clearly visible, and the current here seems the most powerful of all the water channels between the other three islands, mainly because it seems to derive from a deep fracture or joint in the underlying dolostone bedrock. Visually many of the shrubs on the margins of Brother Island appear to be Dogwoods, notably Cornus stolonifera or Red-Osier Dogwood. A large Horse Chestnut (Aesculus hippocastanum) on Brother Island, faces the Third Sister and supports a lovely crop of dense, parti-colored white flower-clusters in early summer. Large willows may be observed here; perhaps these are Black Willow (Salix nigra). This island may provide clues to the aboriginal ecology of various parts of Goat Island and other Islands at the brink of the Falls, although the absence of conifers indicates some disruption in the ecosystem.