A glacial lake is a body of water that forms in a depression created by the movement of a glacier. As glaciers advance and retreat, they can carve out basins that fill with meltwater. These lakes can vary in size and depth, often appearing in mountainous regions where glaciers are present. Glacial lakes are typically fed by melting ice and snow, making them clear and cold. They can also be temporary, disappearing as glaciers shrink due to climate change. Notable examples of glacial lakes include Lake Louise in Canada and Glacial Lake Missoula in Montana.