Interview with G. Brent Dalrymple, Dean and Professor Emeritus at Oregon State University. Dalrymple recounts his childhood in Los Angeles, and he explains how he settled on geology as a major at Occidental and the impact of the plate tectonics revolution that was happening at the time. He discusses his graduate work at Berkeley, and he recounts his field work under the direction of Garniss Curtis on potassium argon dating. Dalrymple explains his decision to join the U.S. Geological Survey after graduate school and his interest in learning more about volcanic rocks and magnetic fields in the Sierra range. He explains how this research solved the problem of continental drift and he discusses his subsequent research on the Hawaiian Island range. Dalrymple discusses his work on earthquake detection, and he describes the advances in K-Ar dating and techniques. He discusses his work on meteorite dating and the light this shed on what killed off the dinosaurs, and he describes his advisory work for the Apollo missions. Dalrymple explains how he became involved in debates with religious communities who insisted the age of the Earth was 6,000 years old and how this turned into his book The Age of the Earth. He describes how geo-dating is relevant for understanding star and galaxy formation and he discusses his tenure as president of the American Geophysical Union. Dalrymple describes what it was like to win the National Medal of Science, and he explains his decision to retire from the USGS and join the administration at Oregon State. At the end of the interview, Dalrymple describes the impact of continental drift research, and he conveys his enjoyment with life in retirement.