slopes, particularly along the eastern margin of the ridge. The entire ridge was glaciated during the last Wisconsin glaciation, which scoured the ridges, left pockets of till, and dumped talus (blocks of rock) off the east side of the ridge. On top of the ridge, the soils are generally thin, highly acidic, low in nutrients, and droughty, but in depressions and other areas where water is trapped by the bedrock or till, there are interspersed lakes and wetland areas. Soils on top of shale are thicker, less acidic, and more fertile. Topography on the top of the northern Shawangunks is irregular due to a series of faults that form secondary plateaus and escarpments. Ice caves Ice caves are deep fissures in the conglomerate bedrock that retain ice through much of the summer, resulting in a cool microenvironment that supports several northern species such as black spruce, hemlock, rowan, and creeping snowberry (Gaultheria hispidula), and bryophytes such as Isopterygium distichaceum. These ice caves are concentrated near Sam's Point in the northern Shawangunks. Larger limestone caverns occur along the lower slopes of the Rondout and Delaware River valleys. Lakes Lakes and wetlands occur mostly on the flat-topped ridges at the northern and southern ends of the area and, to a lesser extent, along the western side of the middle part of the ridge. Lakes and ponds occurring on conglomerate tend to be clear, nutrient-poor, and very acidic, due to limited buffering capacity of the bedrock. The northern Shawangunks have five lakes, the "sky lakes," which are, from north to south: Mohonk Lake, Lake Minnewaska, Lake Awosting, Mud Pond, and Lake Maratanza. The pH in four of the lakes averages about 4 (acidic); Lake Mohonk, which partially overlays shale bedrock and is therefore partially buffered, is closer to neutral pH (7.0). Public lands and preserves The Shawangunks contain mainly public lands as well as several small residential areas. A large portion of the northern Ridge is protected by Minnewaska State Park Preserve, which also now manages Sam's Point Preserve with more than of hiking trails and several climbing areas. Established in 1963, the Mohonk Preserve protects and manages over 8,000 acres of the Shawangunk Ridge, including the world-renowned Trapps climbing cliffs, and features over 70 miles of historic carriage roads and trails. In 2007 Shawangunk Ridge State Forest and Witches Hole State Forest were added. The Long Path long-distance hiking trail follows the