VOLCANIC ACTIVITY OF LASSEN PEAK 



297 



The limit ol' llir lieaxv Tali of ash imt wiml-hoi'iu! was quilc dcdiiitely 

 marked 011 .luiie "^6 and was piolialily within a circle of k'ss than a 

 mile. It liad not, Iiowcmm", a iinirtinii hoink'r. In inakini;' tlie ascent 

 on that day, instead of the rc\2,uhii' trail a more easterly i-outc was taken, 

 leadin^i' np the southeasterly ridge diri'ctly to the iii'e lookout station. 

 This I'idge, which lies in the general direction of the longitudinal oj)en- 

 ing of the crater itself, was fonnd to l)e much moi'e heavily covered 

 with ash than the regular trail. While the main outhursts were usually 

 directly upward in the eruption descrihed, irregular streaks of ash such 

 as the one just noted })rove that there were minor outshoots of volcanic 

 dust in \arious directions. Exaggerated reports of the distance to 

 wliicli stones were thrown seem to have been based upon their being 



Fk;. '■:.. liiE >,ui;Tin\i:sTKi;LY E_nd uf the Ckateii ux June i:>i. Wlifuever tlie steam 

 was blown aside, a crack was visible extending in the line of steam jets. 



found on the outer sIojjcs of the old crater resting uixui the surface of 

 the snow, but the fact that stones are constantly being dislodged from 

 the cliifs by ordinary weathering processes and are rolling down the 

 mountain side shows the need of additional criteria. To avoid mis- 

 taking such stones for those thrown through the air l)y eruption, care- 

 ful search was made on level patches of the old snow so located that it 

 was impossible for stones to roll down upon them. A\'li('i-ever such level 

 surfaces were found thei'e was no evidence at that time of ejected 

 stones falling at a much greater distance than to the lookout Iiouse, 

 certainly at no point over a half mile from the crater. 



In climbing Las.sen Peak from the southeast up to tlie ci'ag u})on 

 which the Forest Service station is built the slope is so steep and rugged 

 that the final ascent is made without any glim]ise of what is ahead. As 

 the last rocks are scaled and one stands on the wind-s\ve[)t crag by the 

 fragments of the little frame building once bound down to the rocks l)y 



