The author of numerous articles on the history of California and the American West, Phelps has also worked extensively in the realm of public history, serving as an interpretive advisor and content editor for a number of historical museums, including the Oakland Museum of California. As campus Executive Director, he has worked extensively to preserve the Galindo Creek section of university property. Phelps holds an MA and Ph.D. in United States History from the University of California, Riverside and a BA in History from San Diego State University. Born and raised in San Diego, he is a member of the San Pasqual Band of Mission Indians of California and a former tribal vice chairman. He lives in the North Bay region with his wife Meri and son Aaron.