Geologists Lon Abbott and Terri Cook teach at Prescott College in Prescott, Arizona. Lon's fieldwork has taken him from the remote mountain peaks of Papua New Guinea to a 15,000-foot-deep ocean trench near Costa Rica--and many places in between. Terri has specialized in rocks from deep-sea hot springs. Her interests in geology and archaeology have led her across six continents. Lon and Terri are also the authors of Hiking the Grand Canyon's Geology.