The Indian Ladder Trail runs along the base of the cliff and was historically called the Lower Bear Path. Halfway down the limestone cliff, the Coeymans formation above meets the Manlius below. At the top of the Manlius, a soft layer of limestone eroded to form a ledge in the cliff face known as the Upper Bear Path. This soft layer is a fine-grained limestone mudrock valued as a source of cement, and limestone is quarried throughout the region for construction. Geologists believe the Helderberg Escarpment existed before the Pleistocene, or glacial period, which began about 1.6 million years ago. Although many cliffs were created by glaciers, this cliff was protected by the ice, which could not move up the vertical rock wall. Only the ice above the escarpment was in motion, carving striations across the surface rock and depositing foreign rocks from other regions called glacial erratics. As the last ice sheet retreated about 10,000 years ago, meltwater flooded the valley to form glacial Lake Albany, and the lake water eventually drained through the Hudson River.
