South Sister NW flank. Right shoulder at skyline is thin sheet of m...
By Volcano Hazards Program
1905 (approx.)
![South Sister northwest flank. Right shoulder at skyline is thin she...](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/full_width/public/vhp_img1239.jpg?itok=_g8FPBMO)
Detailed Description
South Sister northwest flank. Right shoulder at skyline is thin sheet of mafic material from 22ka summit eruption. Red cinders in headwall cirques are layered with dipping lava flows.