154 BULLETIN UNIVERSITY OP MONTANA 



visit to the lake at the same place shows that the water has risen sev- 

 eral feet higher in the lake, to the eaves of the log house in Plate XLII. 



This seems to prove the statement made relative to the closure' of 

 the underground channel. If the lake continues to rise from year to 

 year the results may be disastrous, as it may overflow the bank at some 

 point, doing much damage. 



Echo lake has not received extensive study, and offers a very prom- 

 ising field for a summer's work for some one who wishes to undertake it. 



There are morainal hills a hundred feet or more in height between 

 the lake and Flathead river. Ranchers, in digging wells, pass through 

 alternate layers of sand and gravel containing water. The indications 

 point to the existence of this sand and gravel from Echo lake to or near 

 to Flathead river. 



The canyons in the mountain sides to the east of Echo lake show dis- 

 tinct evidences of glaciation, leading from the slopes down into the valley. 

 These various smaller glaciers from the west side of the Swan range and 

 from the east side of the Mission range merged into one large glacier, 

 which must have pushed down (northward) the Swan river valley. In 

 Plate XXXVII the movement would be from left to right. At the same 

 time a much larger ice mass was moving down the valley of the Flathead 

 river and across Flathead lake. Evidences of this ice mass exist about 

 Kalispell, along the shores of Flathead lake, and in the Mission valley 

 to the south of Flathead lake. At the foot of Flathead lake the large and 

 distinct moraine stretches from the Mission mountains on the east across 

 the end of the lake to the Cabinents on the west, decreasing toward the 

 west, and cut by the outlet of Flathead lake. As the ice river from 

 Swan river valley moved northward it was met, almost at right angles, 

 by the larger ice sheet covering the Flathead valley. The place of 

 meeting should be the valley shown in the middle of Plate XXXVII. 



The Mission range ends as such in the low hills south and west of 

 Echo lake, in the immediate vicinity of the Biological laboratory. These 

 hills may be seen in Plate XXXVII to the left and immediately in front 

 of Flathead lake. This northern end shows distinct evidences of glacial 

 tion. Large boulders, with abundant and deep striations lie at or near 

 the summits. 



The contour of the land indicates that Swan river formely had its 

 course northward, instead of turning to the west as is now the case. 

 When the river and valley were filled with ice, meeting the larger ice 

 mass, the larger mass caused a deflection of the smaller (Swan river 

 valley) mass causing it to pile upon and flow over the lower slopes of the 

 Mission range. This deflection probably aided in carving the present 

 channel of Swan river, where it makes an abrupt turn and passes through 

 a short and steep aescent to the lake. 



The retreat of the main ice sheet was probably more rapid than that 

 of the Swan river valley mass, owing to the close proximity of mountain 

 ranges feeding the latter. The result was a morainal deposit at what 

 should be the surface outlet and what is the underground outlet, of Echo 

 lake. Echo lake therefore appears to be either a portion of the old river 

 bed, or a depression left in the morainal mass by the retreat of the ice. 



