207 



an irregular, winding course follows along the top of tlie volcanic lava- 

 flow iu a general northwesterly direction, leaving the park nearly west 

 of the Upper Geyser Basin. 



Five main channels carry oft" the waters from the park to the valleys 

 I below. On the eastern side of the great water-shed the Yellowstone, 

 Madison, and Gallatin contribute their waters to the Missouri, while 

 the Snake and Falls Eivers on the opposite side add their share to the 

 Columbia. The Yellowstone Eiver, already a magnificent stream be- 

 fore it leaves the mountains, drains more than one-half the area of the 

 park, including the entire eastern border, together with the eastern 

 side of the Gallatin Range, which, through the Gardiner Eiver, pours its 

 waters into the Yellowstone. The streams upon the western slope of 

 the Gallatin Eange empty into the Missouri by the Gallatin Eiver. 

 Both the Gibbon and the Firehole find their sources among springs on 

 the plateau^ and after draining the i)rincipal geyser basins unite to form 

 the Madison. Falls Eiver, a picturesque stream, collects the large 

 drainage frooi the Pitchstone Plateau and the southern end of the Madi- 

 son Plateau, and leaves the park at the extreme southwest corner. 

 Snake Eiver, however, drains the greater -part of the country on the 

 west side of the water-shed, collecting immense bodies of water com- 

 ing from the northern ends of the Teton and Wind Eiver Eanges and 

 the southern slopes of the volcanic plateau. Taken together, these 

 accumulated waters make the Snake a broad river before it leaves the 

 mountains. 



On the x)lateau, upon both sides of the water-shed, occur several 

 large bodies of water, Yellowstone, Shoshone, Lewis, and Heart Lakes 

 being especially noteworthy for their size and beauty. Scattered over 

 the' country, both on the plateau and in the surrounding mountains, 

 are numerous smaller lakes and i^onds, occupying for the most part 

 shallow basins of glacial origin. The view from the summits of eitlier 

 Mount Sheridan or Mount Hancock presents a grand and picturesque 

 scenery of diversified forms, and a country so dotted over with lakes 

 as to receive the appellation of the lake region of the Park. Thou- 

 sands of hot springs add their waters to the cold water of the surface. 

 Meadows, marshes, and swampy areas characterize the entire area in 

 strong contrast with most Eocky Mountain scenery. These lakes are 

 the reservoirs of the larger streams. The Yellowstone is the largest 

 lake in North America at so high an elevation (7,741 feet). It has a 

 surface area of 121 square miles, and an indented shore-line of nearly 

 100 miles. Only preliminary soundings have as yet been made, but over 

 a very considerable area the depth is known to be more than 250 feet. 

 Less than G miles from the Yellowstone, in a deep depression on the 

 I)lateau, lies Shoshone Lake, with an area of nearly 12 square miles. 

 A short distance to the southward, at the west base of Mount Sheridan, 

 occurs Lewis Lake, measuring 4 J square miles, and on the opposite side 



