The third major glaciation of the Pleistocene in Alpine Europe; the penultimate Alpine glacial advance. It started 250,000 years ago and lasted over 100,000 years. The Riss, during which mountain glaciers descended from the highlands, followed the Mindel-Riss Interglacial Stage and preceded the Riss-Würm Interglacial Stage, both periods of relatively moderate climatic conditions. The Riss is correlated with the Gipping Glacial Stage of Great Britain and the Saale Glacial Stage of northern Europe. Like the Saale, the Riss Glacial Stage included two major phases of ice advance separated by a period of more moderate conditions. The Riss Glacial Stage is roughly contemporaneous with the Illinoian Glacial Stage of North America.