Road guide to volcanic deposits of Mount St. Helens and vicinity, Washington /
Doukas, Michael P.
[Reston, Va.?] : Dept. of the Interior, U.S. Geological Survey  ; Denver, CO : For sale by the Books and Open-File Reports Section,
1990.
Shipping list no.: 90-211-P.
Includes bibliographical references (p. 52-53).
Volcanic ash, tuff, etc.