Mount Hood

A short road trip from Montana across Idaho to Oregon to understand Mount Hood, an active Cascade volcano.
References:
Oregon Geology by Elizabeth and William Orr, sixth edition, 2012, Oregon State University Press, 304 pages.
Roadside Geology of Oregon, second edition, 2014, Marli B. Miller, Mountain Press Publishing Company, 387 pages.
Thanks to Meghan, Peter, Olivia, Philip and all the others providing the sanctuary at Breitenbush Hot Springs.