248 OUR NATIONAL PARKS 



of the Sierra lakes and streams are invisible, 

 or nearly so, under certain weather conditions. 

 This is noticed by mountaineers, hunters, and 

 prospectors, wide-awake, sharp-eyed observers, 

 little likely to be fooled by fine whims. One of 

 these mountain men, whom I had nursed while a 

 broken leg was mending, always gratefully re- 

 ported the wonders he found. Once, returning 

 from a trip on the head waters of the Tuolumne, 

 he came running eagerly, crying : " Muir, I Ve 

 found the queerest lake in the mountains ! It 's 

 high up where nothing grows; and when it isn't 

 shiny you can't see it, and you walk right into it 

 as if there was nothing there. The first you 

 know of that lake you are in it, and get tripped 

 up by the water, and hear the splash." The 

 waters of Illilouette Creek are nearly invisible in 

 the autumn ; so that, in following the channel, 

 jumping from boulder to boulder after a shower, 

 you will frequently drag your feet in the appar- 

 ently surfaceless pools. 



Excepting a few low, warm slopes, fountain 

 snow usually covers all the Yosemite Park from 

 November or December to May, most of it until 

 June or July, while on the coolest parts of the 

 north slopes of the mountains, at a height of 

 eleven to thirteen thousand feet, it is perpetual. 

 It seldom lies at a greater depth than two or 

 three feet on the lower margin, ten feet over the 

 middle forested region, or fifteen to twenty feet 



