42 BOTANICAL SURVEY OF THE CCEUR D'ALENE MOUNTAINS. 



be necessary to carry the flume or channel conveying the water along 

 the valley of the South Fork and around the east shore of Lake Oceur 

 d'Alene. This would involve the construction of hundreds of miles of 

 conduits if the contour line was followed. At this point in the river we 

 should have the slimy water delivered from the concentrators, which is 

 wholly untit for irrigation purposes while charged with siliceous and 

 metallic elements. The waters of the North Fork would not be open 

 to this objection, but the conduits necessary would not be shorter. 

 The same difficulty applies with added force to the St. Joseph, as the 

 length of the necessary water channels would be even greater. 



The waters of Lake Cceur d'Alene can be utilized in a limited way 

 for irrigation purposes. It is within a reasonable range of possibilities 

 to dam the lake at Post Falls, and raise its waters sufficiently to irri- 

 gate a large portion of the immediate valley of the Spokane River, 

 But a dam high enough to hold back a sufficiency of the surplus 

 water of the spring freshets that the summer stage in the river below 

 would be high enough to maintain the water power at Spokane would 

 submerge permanently all the land which adjoins the slack-water por- 

 tion of the Cceur d'Alene, St. Joseph, and St. Mary rivers, besides a 

 large quantity abutting upon the shores of Lake Cceur d'Alene. The 

 quantity of land which could be irrigated from this source would be 

 relatively small. Only the lower benches along the Spokane could be 

 reached; the upper are from .'10 to 150 meters (98 to 490 feet) above the 

 lake. For the same reason any scheme to take water directly from any 

 of the C<eur d'Alene streams to irrigate the lauds of the Spokane valley 

 would not be a financial success. 



FOREST RESOURCES. 



The Cceur d'Alene basins are or, perhaps more properly, have been 

 a densely forest-covered region. The humidity of the climate and the 

 great depth to which the zone of decomposition of the rocks has extended 

 have combined to favor a surprisingly great development of the forest 

 part of the flora. The growth of timber is by no means uniform through- 

 out the region. Many agencies have operated and are still active to 

 produce present conditions, which will be considered under the head of 

 "Forest destruction." 



At the present time the areas which have the heaviest stand of living 

 timber are the central portions of the St. Mary and St. Joseph valleys, 

 the valleys of the various forks of the St. Joseph, and the western 

 region of the ^North Fork basin. The density of the forest varies with 

 its position as regards elevation and exposure. It is far heavier in the 

 bottom lands and on the mountain sides where the angle of the slopes 

 does not exceed 35° nor the elevation 1,250 meters (4,100 feet) than else- 

 where. The northern faces of the ridges have also invariably a thicker 

 stand of trees than any of the others, provided the slope is not too great. 

 The sides fronting the west come next, then those that face the east, 



