THE TWIN LAKES GLACIATED AREA 293 



for a greater distance than the moraine below the lower lake. A 

 third morainic ridge (Fig. 1, 2), a part of a recessional moraine, is 

 developed on the south side, just down-stream from the one just 

 mentioned at Interlaken. It runs below the level of the lower lake, 

 and is not found on the north side of the lakes. Masses of morainic 

 drift occur within the rock-gorge, but irregularly distributed, rather 

 than in the crescentic shape characteristic of recessional moraines. 

 In all cases these moraines are small, forming a belt of rolling drift 

 20 to 30 feet high and not exceeding several hundred feet in width. 



Above Twin Lakes village, in the rock-gorge of Lake Creek, the 

 drift occurs irregularly and is not aggregated into moraines. Erosion 

 and not deposition was here the rule. From the base of the moun- 

 tains to the Arkansas the drift occurs in simple morainic embank- 

 ments. There is an intermediate area, on both north and south 

 sides, where an intermediate relation holds. On the south side of 

 Lake Creek the south lateral rests against the lower slope of Lost 

 Canyon Mountain, its crest drooping slowly to the east and interrupted 

 only where cut by streams flowing into Lake Creek. At these places 

 a typical moraine section is shown, as the moraine was built across 

 the mouths of the lateral valleys which were occupied by streams in 

 their lower course and entered the main valley well below the level 

 of the glacier surface. Opposite the intervening divides the moraine 

 crest is continuous with the crest opposite the valleys where it has not 

 been cut away. Sections on the inner face of the moraine opposite 

 the divides, however, frequently show rock in place; and while this 

 inner slope is drift-covered, it appears that the drift forms but a veneer 

 over the truncated spurs of the rock divides between adjacent lateral 

 valleys, so that the apparently simple moraine along the base of Lost 

 Canyon Mountain is really a cut-and-fill affair, moraine-veneered 

 truncated spurs opposite the divides, and typical moraine embank- 

 ments opposite the lateral valleys. This double character holds for 

 four miles along the south side of the valley, and for a short distance 

 along the north side back of Twin Lakes village. 



4. The Clear Creek morainic system. — This paper is concerned 

 with the Lake Creek region, yet it is permissible to note that the 

 history which has been outlined above for the glacier occupying the 

 valley of Lake Creek was duplicated in every essential feature by the 



