SNOW SLIDES IN THE CANADIAN ROCKIES. 



339 



snow the greater the havoc wrought when 

 it leaves its rocky home on the summit and 

 starts for the bottom of the canyon. In 

 some cases the snowfall is light for sev- 

 eral years, and the snow slides are small. 

 Then comes a winter when the snow piles 

 up 10 or 20 feet deep on the hills. Then 

 look out for breakers. 



In the springs following the lighter falls 

 of snow the slides come down narrow 

 gulches that have been worn in the rock 

 by this process ; but when the heavy snow 

 comes these gulches overflow their banks, 

 so to speak, and the timber that has been 

 growing over the old slide for perhaps 

 io or 12 or 15 years is swept away, and 

 the debris added to the accumulation 

 below,. 



Even the small slides bring with them 

 some big trees that are caught here 

 and there, and all of them bring large 

 quantities of rock. The native granite 

 which forms the crest of all: these great 

 mountains is more or less broken from the 

 effects of internal heat which raged there 

 ages ago. The water settles in these seams, 

 freezes when the cold weather comes, and 

 thaws in spring. This process keeps break- 

 ing off fragments of the rock, and these 

 tumble down the mountain sides. When 

 a bed of 10 or 20 or 40 acres of snow starts 

 from the top of the mountain it picks up 

 many of these blocks, and the inclined 

 walls of the gulches gradually force the 

 whole mass into the narrow confines of the 

 cut. Then, as the weight and size of the 

 mass and the degree of pitch from point to 

 point increase, this great body moves 

 faster and faster down the mountain 

 side. 



At intervals, along the tracks are per- 

 pendicular walls of solid granite, ranging 

 in height anywhere from 20 to 200 or 300 

 feet. Imagine, if you can, a mass of snow, 

 ice, rocks and trees coming down a great 

 inclined chute, say 50 feet wide at the top 

 and 50 feet deep.. This chute is, as I have 

 said, built on an incline of 50 or 60 degrees, 

 with walls so steep you could not climb 

 one of them at the rate of more than ^ 

 mile an hour. The slide increases in veloc- 

 ity as the distance increases from the start- 

 ing point. We will assume that when it 

 reaches the first perpendicular wall it is 

 going at a rate of 10 miles an hour, or at 

 the ordinary speed of a slow freight train. 

 When it takes its first perpendicular leap 

 it goes down with a frightful velocity and 

 from there to the foot of the mountain it 

 moves like a hurricane. We will assume 

 that at the foot of this first fall the same 

 rocky chasm receives the moving mass and 

 confines it within narrow limits. Nearly 

 all these gulches curve here and there, and 

 when the slide strikes a shoulder of one of 

 these abrupt turns its velocity is checked; 



but as the load accumulates behind, it is 

 forced ahead, and, going on down, it finally 

 reaches the second perpendicular wall and 

 takes a second plunge toward Hades. Then 

 it moves on with increased force and ter- 

 ror. Finally the whole great mass of ruin 

 reaches the bottom of the canyon, or what 

 may be called its moraine. There the gulch 

 ends, and the snow, being still pressed and 

 pounded from behind by thousands of tons 

 of other snow and rocks and ice, spreads 

 out over a tract of perhaps 5 or 10 or 20 

 acres of ground. 



The head of the procession has now 

 reached the level of the creek and stopped. 

 The great weight and the great body of 

 snow and rocks behind keep forcing the 

 other sections down and piling them up 

 until, when the last of the avalanche ar- 

 rives, this great moraine is covered with 

 snow and rocks and timber from end to 

 end, from side to side, 50 to 100 feet deep; 

 a perfect mountain which has come down 

 from the top of the mountain. 



I wish I could describe the noise 

 these snow slides make. Did you ever 

 go into an old fashioned grist mill and 

 hear the stones revolving on each other? 

 If so, multiply the volume of sound you 

 heard there by 10,000. Did you ever stand 

 beneath a high bridge and let a freight 

 train pass over your head? If so, multiply 

 the effect of that by 10,000 and you may 

 possibly realize the terrible uproar that 

 comes from one of these snow slides. 

 It is the most appalling, the most heart- 

 rending, and the most nerve destroying of 

 anything I have ever listened to. If there 

 was nothing but snow moving it would 

 make little noise; but there are perhaps 

 thousands of tons of granite mixed with 

 the snow, in blocks varying from the size 

 of your head up to that of a box car. 

 Then, in among these, are a greater or less 

 number of logs and brush, being broken 

 into all sorts of shapes, and some of them 

 being ground into splinters. 



We camped within 100 yards of one of 

 these great terminal moraines. We went 

 in before the regular spring slide had come 

 down. In reaching our camp we crossed 

 this vast deposit of broken granite and old 

 logs. The mass is perhaps 200 yards wide 

 and 50 to 100 feet deep,. The trail leads 

 across this field and winds hither and 

 thither in order that safe footing may be 

 found for man and beast. How long it has 

 taken to form this deposit no one knows, 

 but probably thousands of years. 



We pitched our tent in a forest, of .great 

 cedars, about 100 yards from the North 

 edge of the moraine, partly in order that 

 we might have a good view of the great 

 slide when it should come.. We watched 

 for it day and night. Finally, after we 

 had been in camp about 2 weeks, and when 



