82 The Shoshone Island. 



the surface of this ash bank. The trees of 

 largest size were Yellow Pine (Pinus Ponde- 

 rosa), some of them three or four feet in diam- 

 eter and in good healthy condition. All this 

 forest growth was on the surface of a sheet 

 of volcanic ashes. 



Evidently all this heavy timber came from 

 a replanting that occurred long after the vol- 

 canic eruption. For aught that appears there, 

 several successive generations of trees may 

 have come and gone since that shower of 

 ashes fell. When this ashes fell it lay lightly 

 for a time. Rains and snows falling on it set- 

 tled it down with the help of its own gravity. 

 Where it is now twenty feet deep it must have 

 at first been forty or fifty feet deep, a depth 

 inconsistent with any thought of the survival 

 of any forest tree on which it fell. 



It slowly diminishes as one recedes from 

 the mountain until at forty or fifty miles it 

 disappears. 



After a good deal of search for some 

 exposure of the old surface upon which all 

 this spent fire material had fallen, I was for- 



