426 LAKE CHELAN 



has cut since the retreat of the glacier. Bridge creek has numer- 

 ous branches, and at the junction of each of these branches 

 similar phenomena are observed, although in case the branches 

 are nearly equal in size the bench or rise in the glacial valley 

 is not as marked as in the case of smaller branches. From all 

 indications it appears that the ice must have been at least 3,000 

 feet deep in this gorge of the Stehekin, since several of the smaller 

 branches join the main glacier at that height above its bed. 



Lake Chelan is between 50 and 60 miles in length and from 

 half a mile to a mile or more in breadth. Except near its lower 

 end, it is enclosed throughout its course between high steep 

 walls, rising at angles of 40° to 45° directly from the water's 

 edge to an altitude of 5,000 or 6,000 feet above the sea. The 

 elevation of the lake above the sea is 1,100 feet, and its canon 

 walls rise 4,000 or 5,000 feet above its surface. Nearly all the 

 streams which flow into it are small, and tumble over its walls 

 in a series of cascades. There is but one stream of magnitude, 

 Railroad creek, which is tributary to it. This, which is upon 

 the west side, heads in the divide of the Cascade range, among 

 the high peaks, where its sources are fed from living glaciers 

 and its valley is a glacial gorge. 



Near its upper end the lake is narrow and its depth increases 

 gradual^, but about midway of its length it reaches a depth of 

 fully 1,400 feet, its bottom being, therefore, 300 feet below sea- 

 level. Thence its depth diminishes gradually to its lower end, 

 but not as regularly as it increases. The rock walls which en- 

 close the lake are strikingly parallel to one another. The high 

 mountains which border it at its head extend down nearly to 

 its foot, and then suddenly break away to the lower country, 

 first upon the east side and then upon the west. 



The dam by which the lake is formed is the terminal moraine 

 of the glacier. The lake is now drained by a stream which has 

 cut through this terminal moraine, and after a short course of 

 three miles and a descent of 400 feet joins the Columbia. Above 

 the present outlet are indications of former outlets of the lake 

 in the shape of coulees, cut through from the west, or rather 

 south, side of the lake to Columbia river. The lower of these, 

 Knapps coulee, which leaves the lake at about three miles above 

 its present outlet, has an elevation, at its summit, of about 300 

 feet above the present level of the lake, with a sharp descent to 

 Columbia river at its lower end. The other leaves the lake at a 

 point about 10 miles above its present outlet, and is much 



