In the entire Park there are about thirty-six named lakes with a total area of nearly 165 square miles. Of these lakes, twenty-one, with an area of 143 square miles, are on the Yellowstone slope; eight, with an area of perhaps two square miles, are on the Missouri slope; and seven, with an area of about twenty square miles, are on the Snake River slope. The four principal lakes--Yellowstone, Shoshone, Lewis, and Hart--are clustered near the Continental Divide at its lowest point, the first being on the Atlantic slope, and the others on the Pacific. There are upon the various streams of the Park no fewer than twenty-five interesting water-falls, where the streams descend from the Park plateau to the lower surrounding country. MOUNTAIN SYSTEM As the Yellowstone River is the most important stream in the Park, so the Absaroka Range, in which it has its source, is the most important mountain system. It extends north and south along the entire eastern border. To the south it is prolonged under the name of the Sierra Shoshone Mountains as far as the Wind River Valley, while north of Soda Butte Creek it extends to the Great Bend of the Yellowstone under the name Snowy Range. The various larger summits are remarkably uniform in elevation. From Index Peak on the north to Yount Peak on the south, there are more than thirty named mountains with an average altitude of 10,400 feet. The variation from this mean is slight. The range, throughout its length, is full of noble views, and, as seen from across the Yellowstone Lake, is one of the finest exhibitions of mountain scenery on the continent. The next most important range is the Gallatin, situated in the north-west corner of the Park, at the head of the Gallatin River. It has about seventeen named peaks, with an average altitude of 9,800 feet. The highest peak, Electric, is the loftiest mountain in the Park. The Washburn Range, a detached mountain system, originally known as the "Elephant's Back," is situated between the Grand Cañon of the Yellowstone and the Gardiner River. It has seven christened summits, with an average altitude of 9,800 feet. The most conspicuous peak of the range, as well as the most noted mountain of the Park, is Mt. Washburn. The Red Mountain Range is a small, detached group of mountains between Hart and Lewis Lakes. Its principal summit, Mt. Sheridan, affords probably the finest view to be had in that entire region. The Teton Range lies mainly outside the Park, its northern spurs barely touching the southern boundary. It extends north and south along the west shore of Jackson Lake, and is a very noted range of mountains. Its highest summit, the Grand Teton, has no competitor for altitude nearer than Fremont Peak, seventy-five miles distant. The Big Game Ridge lies along the south boundary of the Park, and is the source of the Snake River. It has six named peaks, with an average altitude of 9,800 feet.