- David Samuel Tucker is a geologist, author, and union organizer in Washington state. He is a research associate at Western Washington University. He was an instructor at North Cascades Institute, and the director of the Mount Baker Volcano Research Center (now closed). He writes the blog Northwest Geology Field Trips, a blog aimed at laypeople detailing where to find interesting geology in the Pacific Northwest. In 2015, he published a popular book on Washington geology, Geology Underfoot in Western Washington. He resides in Bellingham, Washington. In the 1980s he worked as a mountaineering guide in the Cascades, Mexico, and South America.