26 NORTH AMERICAN FAT-NA. [xo. 16. 



and clitt's. l)ut for sonio uiiiiccouiitable reason even rarer than the cony, 

 is the bushy-tailed wood rat or pack rat {Xr()t(>)H(( ci)i('>-ei(), which, if 

 my memory serves me correctly, is less coiiiiiion on Shasta than on any 

 other mountain T have visited in the AVest. The mountain chipmunk 

 {Eut(())ii((s sriic.f) and ^i;olden ground squirrel {CaUosperiiiophiluH rhryso- 

 deiniN) inhabit the tongues of pines on the ridges, and not infrequently 

 live in burrows among the bare rocks. ^larinots. it is safe to assert, are 

 altogether absent. We completely encircled the ])eak in the neighbor- 

 hood of timberliue, and examined innumerable ledges and rock slides, 

 such as on other mountains are inhabited by marmots, but without find- 

 ing so much as a track or sign or even a bleached bone to indicate that 

 any member of the genus Arefomy.s had ever inhabited Shasta. In 

 former days the bighorn {Oris eaiiadensis) was common here, but now 

 the occasional fragment of a skull or the scattered i)arts of a skeleton 

 are all that remain. In fall the old bucksof the CoTumbia black-tail deer 

 wander u]) on the higher ridges. Here and there, i)articularly in the 

 shelter of the prostrate white-bark ])ines, tracks and dung of rabbits 

 were seen, but in spite of all our efforts no member of the party succeeded 

 in tinding a rabbit on the mountain. The species is probably the Sierra 

 rabbit {Lepiis Ihimathemis), though from the large size of some of the 

 dung pellets 1 was inclined to suspect the presence of LejiKs campestris. 



AVALANCHES. 



During the loosening of the snow in spring, avalanches must be very 

 common on the higher slopes, and it is probable that they exert a 

 controlling influence in determining the timber areas above the limit of 

 continuous forest. jSTothing forces itself on the observation more firmly 

 than the iieculiar way in which the white-bark pines are restricted to 

 the long radiating ridges where they form narrow tongues, separated 

 by broad intervals of steep slopes and basin shaped valleys. While it 

 might be hazardous to assume that the absence of trees from these 

 extensive slopes ami basins is due mainly to avalanches, tlu^ fact 

 remains that the tracts they occupy along the tops and upper slopes 

 of the ridges are entirely out of reach of these resistless engines of 

 desti'uction. 



Now and then, however, an avalanche, taking an unusual course, 

 reaches the outskiits of one of these tongues of alpine pines and 

 snatches up ami carries below all that lie Avithin its path. This is 

 evident from the weathered trunks and roots often found at the bot- 

 toms of slopes where trees have never grown. 



The most consi)icuous i)ath of a recent avalanche observed is on Cold 

 Creek, between the deep canyons of Mud and Ash creeks (fig. l."}). Here 

 an avalanche of unusual size must have shot dowri the higher slopes 

 until it reached the upper edge of the continuous forest of Shasta firs, 

 where, instead of stopi)ing, it cut a broad swath tliiougli the huge 

 trees, tearing them up by the roots or snaiq)ing tliem off and carrying 



