Smithsonian Report. 1935. — Atwood 



Plate 5 



1. Llao Rock Viewed From the South. 

 Beneath the massive dacite flow at a point marked A is an exposure of glacial till. At B a similar deposit 

 rests upon a striated surface. The contact between the lava and underlying till suggests that ice existed 

 on the mntmtain dnrinc tlie first stages of the eruption which produced Llao Rock. 



2. The Massive Llao Flow which Descended upon a Glacial Landscape 



Filling the U-Shaped Valleys and Burying the Morainic Debris. 



The lower portion of the cliff which rises almost vertically from the water's edge is composed of alternating 



layers of lava and volcanic ejectamenta recording the growth of the young Mount Mazama. 



OfBcial photograph. U. S. Army Air Corps. 



3. Crater Lake Viewed From the Northwest. 



AttheleftisMount Scott, the highest elevation in the park. On the far side of the rim is the U-shaped val- 

 ley of Sand Creek, usually referred to as Kerr Notch. 



