North Point, also known as Sheboygan Point or the Sheboygan Reef, is an exposed shelf of rock along the Lake Michigan shoreline where the uppermost layer of bedrock protrudes through the surrounding glacial drift. This bedrock, known as Niagara limestone, is part of the same bedrock course as the outcropping in New York that forms Niagara Falls. A Silurian dolomite formed by the deposition of marine sediments during the Paleozoic age, 425 to 405 million years ago, it preserves evidence that this area was once undersea, including ancient coral reef structures and other marine fossils. Striations, or scratches on the bedrock surface, indicate the passage of glaciers over this area during the Ice age.