The North American Cordillera is home to a greater diversity of volcanic provinces than any comparably sized region in the world, owing to the interplay among changing plate-margin interactions, tectonic complexity, intracrustal magma differentiation, and mantle melting. Published in individual parts (Chapter B-Chapter Q), the field trips in the guide book collection links to detailed guides to areas such as Mount St. Helens and Mount Hood, featuring history, maps, photos, local information, and a road log.