Alpine lake

Alpine lakes are lakes or reservoirs at high altitudes, usually over 5,000 feet (1524 metres) above sea level, or above the tree line.
Alpine lakes are usually clearer than lower lakes because the cold water reduces the speed and amount of algae and moss growing in the water. Often the lakes are surrounded by varieties of pine trees, aspens, and other high altitude trees.
Yellowstone Lake is an alpine lake, and so is Lake Baikal.