Submerged riverscapes, unique rock formations with gumdrop-like pinnacles, rocky folds, and steep escarpments define Eagle Wing Group, where rocky shoals beside deep water reveal the Thousand Islands region's geological, historical, and ecological diversity. The shoals preserve traces of glacial phases and fault lines, including flat-sided boulders probably plucked from a distant outcropping by a glacier and dropped as the ice melted, and abrupt cliffs formed where the earth's crust was displaced by differential movement of large sections of rock. As residents of Grindstone Island traveled back and forth to Clayton carrying provisions, local legends told of mishaps, with boats lost to the Wing's rocky teeth in summer squalls and automobiles lost through the ice in winter, their remains beneath the river's surface. Owned by the Thousand Islands Land Trust, the Eagle Wing shoals are among the last natural island nesting sites for the threatened Common Tern remaining in the Thousand Islands.