22 BOTANICAL SURVEY OF THE C(EUE d'aLENE MOUNTAINS. 



black current of Japan can in any considerable degree exert an influ- 

 ence on the temperature of such a vast amount of air as must be in 

 motion to account for the effects produced by this wind. It is more 

 reasonable to suppose that the real origin of the chinook is in the 

 equatorial regions of the earth, and that in truth it is an outflow of 

 heated air from these regions toward the polar area. In order to pass 

 the high snowy barriers of the Cascades, which it must do to reach 

 us from the southwest, and still to retain a sufficient degree of warmth 

 to exert the marked influence that it does when it reaches the Couir 

 d'Alenes, it would seem to be absolutely necessary that the initial 

 temperature under which it starts should be very considerable. 



The heat carried by the wind is so great that not only does it produce 

 marked effects in the Rocky Mountain region, but it even extends in a 

 lesser degree as far east as the Missouri River in North Dakota. 



The supposition that the chinook blows only in the spring and winter 

 is a mistake. My observations record t]\a fact that a, wind in every 

 respect identical with the dry chinook prevails throughout the greater 

 portion of the summer months on the summits of the high divides, 

 while it is perfectly calm below. 



It is noticed that an odor, frequently said to be " spicy," often accom- 

 panies the chinook. A popular fancy ascribes this feature to ema- 

 nations from the spice gardens of Asia wafted across to the shores of 

 America on the wings of the chinook. These winds certainly have a 

 peculiar odor, but it can not be called spicy. It rather resembles that 

 which comes with the hazy atmosphere of our so-called Indian summers. 



MINERAL DEPOSITS. 



The economic features of the ('(cur d'Alenes group themselves very 

 naturally under three heads: mineral deposits, agricultural capacities, 

 and forest resources. 



We will iirst consider mineral deposits, as at the present time the 

 output of its mines is by far the most valuable product of the country. 



The Cceur d'Alenes are essentially a mineral-bearing region, for, with 

 the exception of the portion along the St. Mary and the St. Joseph riv- 

 ers and the area northeast from Lake Ceeur d'Alene covered with 

 basaltic outflows, no considerable portion of these mountains has been 

 found, when prospected, devoid of metalliferous veins. 



It is a long time since valuable minerals were first discovered here. 

 At the building of the Mullan road, in 1861, prospectors were found look- 

 ing for and testing placers in the valley of Wolf Lodge Creek. Before 

 this time some parties must have found their way into the North Fork 

 basin, as very old prospect holes buried in the depth of the forest tes- 

 tify. Hudson Bay Company trappers doubtless found gold in this 

 region at a very early date, but t lie records, if any, were unwritten, and in 

 the process of time became mere dim recollections. It was not until the 

 fall and winter of 1883 that it became generally known that valuable 



