The Last Glacial Maximum (LGM) refers to the time of maximum extent of the ice sheets during the last glacial period, between twenty-six thousand five hundred and nineteen thousand to twenty thousand years ago.
The Younger Dryas will follow the Last Glacial Maximum.
This ice extends northward to cover Svalbard and Franz Josef Land and eastward to occupy the northern half of the West Siberian Plain, ending at the Taymyr Peninsula, and damming the Ob and Yenisei rivers forming a West Siberian Glacial Lake.
Alpine glaciers advance in addition to the large Cordilleran Ice Sheet in Canada and Montana, covering much of the Rocky Mountains in the United States.
Ice sheets also cover Tibet (scientists continue to debate the extent to which the Tibetan Plateau was covered with ice), Baltistan, Ladakh, the Venezuelan Andes, and the Andean altiplano.