14 BOTANICAL SURVEY OF THE CCEUR D'ALENE MOUNTAINS. 



localities in the main range of the Bitter Hoots. I estimate that the 

 places enumerated above, at an altitude of 1 ? 200 meters (or about 4,000 

 feet), have an annual precipitation of 200 cm. (or about 100 inches) of 

 water. For the remainder of the region it varies between 150 and 1320 

 cm. (59 and 87 inches). The snow at elevations below 700 meters 

 (about 2,300 feet) usually attains a maximum depth not exceeding 1 

 meter (3.3 feet) for points in the lower portions of the valleys and 1.5 

 meters (4.0 feet) for points in the central and upper portions. Above 

 this the depth rapidly increases. At 1,500 meters (5,000 feet) it will 

 average 5 to meters (15 to 20 feet), and at 2,100 meters (0,000 feet) 

 perhaps 7 or 8 meters (23 to 20 feet.) This, however, does not represent 

 the true total amount of snow that falls. This is always quite damp 

 and settles very rapidly; besides, there is no frost in the ground 

 throughout the forested portions of the mountains, even at the highest 

 elevations, and the snow melts constantly from beneath. 



The amount of precipitation tliat is given for the various localities 

 cited above is of necessity based upon estimates derived from other 

 sources than actual yearly measurements. There are no complete tem- 

 perature or precipitation records in existence for any point within the 

 Ccenr d'Alene basins. For the present we are obliged, therefore, to 

 estimate from fragmentary observations. 



Throughout the areas of maximum precipitation the average number 

 of days during the year on which rain or snow falls is two hundred. 

 For the western areas of the North Fork basin this number is the 

 result of personal observations extending over a period of nearly nine 

 years. For the St. Joseph and St. Mary basins I have no complete 

 observations, but the denseness and size of the forest growth form a 

 pretty accurate criterion by which to judge, and accepting these as a 

 standard, the yearly period of rain and snow in these basins is no less 

 than in that of the North Fork. Over these areas an average fall of 

 rain or snow, reduced to water, is 2.2 cm. (about 1 inch) in twenty-four 

 hours. I have many times measured the fall during twenty-four hours 

 in the months of March, April, -June, and October in the North Fork 

 basin and found 4.5 cm. (about 2 inches) a common occurrence. A total 

 fall of 15 cm. (about inches), as a result of a rain storm of three days' 

 duration in March, October, or November, has frequently been noted. 

 In my estimates I have disregarded these measurements to some extent 

 and placed the average daily precipitation during two hundred days 

 at 1,3 cm. (somewhat in excess of one-half inch). We can also form 

 some estimate of the amount of water that falls throughout these 

 mountains by taking the forest growth as a basis. The amount of the 

 yearly precipitation for Spokane has been given as nearly 00 cm. (about 

 35 inches). Spokane is situated, in a direct line, about 80 kilometers 

 (50 miles) from the extreme western mountain rim of the North Fork 

 basin and about 00 kilometers (37 miles) from the western base of the 

 same. The city is located at the eastern termination of the open plains 



