THE PHYSIOGRAPHY OF THE FLATHEAD LAKE REGION. 20S 



caused the waters of Swan river to be hemmed in between the Swan range 

 and this glacial matter. When the river made its new channel to the west- 

 ward the old channel was abandoned and soon filled up, owing to the 

 fact that it had little fall, and was probably surrounded by dense forests 

 such as now cover the region. A number of deeper places still 

 hold water, forming some of the lakes in that region. The nearest 

 of these to Swan river is Rost lake, which is less than two miles 

 from the river. Next is Echo lake, north and west. It is quite certain 

 that Echo lake was not a portion of the old river bed, but was formed by 

 glacial action. Still farther north is Blaine lake, not yet visited, but 

 lying in the old river valley. 



Rost lake is nine miles distant from the laboratory northeast. It is 

 about a mile long and less than ten feet deep in the deepest portion. 

 In most places the water is less than three feet deep. It is bordered by 

 dense forests, and is a dead lake, which in a short time will be a peat bog 

 similar to many other swamps in the region. 



Echo lake lies north and a little east of the laboratory. It is a land 

 locked lake, with no surface outlet. Notwithstanding this it has several 

 species of fish. Its outlet is underground through glacial drift, coming 

 to the surface through large springs whose waters flow into Flathead 

 river. The surface of Echo lake is quite unstable, and is likely to rise or 

 fall any season. The lake has had very little study. 



Swan lake has previously been mentioned. It is reached by wagon 

 roads from the laboratory, the shortest being about eight miles long, the 

 other about fourteen. Swan lake for the greater portion of its length 

 is but an expansion of the river, hemmed in between the Swan and Mis- 

 sion ranges. Its location may be understood by an examination of the 

 map. Fig. 4. This map is incorrect in part, as the upper end of the lake 

 widens into a circular bay some two miles broad, bordered on the south 

 by a large swamp. This swamp is covered densely with vegetation, and 

 gradually gives way to grassy meadows, which in turn are bordered by 

 dense forests. 



The delta of Flathead river (Plate XLVIII) is worthy of extensive 

 study, and is a good illustration of the method of filling up by sediment 

 from a river. Very little sediment has been deposited by Swan river as 

 compared with the Flathead. This is to be expected, since the former 

 carries much less water than the latter. But the difference is very 

 marked. 



West of Flathead lake nothing has been done, and consequently little 

 can be said concerning its physiography. This hasty and superficial view 

 of the region will give those at the station an idea of the country in gen- 

 eral, and will suggest more detailed study in many lines. There is still 

 much to be done. The higher slopes of the Mission and Swan ranges 

 have had very limited study. There are many lakes not yet visited. 

 Much is left for the work of the future. 



