Spiral Butte Andesite (WA)
Tertiary
Pliocene
Quaternary
Pleistocene
Not synopsized to date. Crops out on both sides of White Pass Highway from summit to 3 mi east of Spiral Butte and on west and northwest of Tumac Plateau, Yakima Co., WA (Ellingson, 1972).
Cascades province
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
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