Last Glacial Period River, which in turn was formed during an earlier glacial period. In its retreat, the Wisconsin Episode glaciation left terminal moraines that form Long Island, Block Island, Cape Cod, Nomans Land, Martha's Vineyard, Nantucket, Sable Island, and the Oak Ridges Moraine in south central Ontario, Canada. In Wisconsin itself, it left the Kettle Moraine. The drumlins and eskers formed at its melting edge are landmarks of the Lower Connecticut River Valley. In the Sierra Nevada, there are three named stages of glacial maxima (sometimes incorrectly called ice ages) separated by warmer periods. These glacial maxima are called, from oldest to
Glacial Lake Columbia Glacial Lake Columbia Glacial Lake Columbia was the lake formed on the ice-dammed Columbia River behind the Okanogan lobe of the Cordilleran Ice Sheet when the lobe covered of the Waterville Plateau west of Grand Coulee in central Washington state during the Wisconsin glaciation. Lake Columbia was a substantially larger version of the modern-day lake behind the Grand Coulee Dam. Lake Columbia's overflow – the diverted Columbia River – drained first through Foster Coulee, and as the ice dam grew, through first Moses Coulee, and finally, the Grand Coulee. The Cordilleran ice sheet also blocked the Clark Fork River and