T. Scott Bryan earned degrees in geological sciences at San Diego State University and the University of Montana. He spent fourteen summers working as an interpretive ranger in Yellowstone National Park and later served in the Volunteer in Parks program. He was one of the founding directors--and the first president--of the Geyser Observation and Study Association and is the author of The Geysers of Yellowstone and GSA's Arizona Rocks! He is also the coauthor of The Explorer's Guide to Death Valley National Park, written with his wife, Betty Tucker-Bryan. Bryan is retired as emeritus professor of geology and astronomy at Victor Valley College in Victorville, California, and now lives near Tucson, Arizona.