[4] During his BYU graduate studies, Underwood worked as an LDS Seminary teacher at Thunderbird High School in Phoenix, Arizona from 1977 to 1981.
[4] He was then a religion professor at Brigham Young University–Hawaii from 1992 to 1999, where he was elected Teacher of the Year multiple times.
[6] In 2007 Underwood created a Mormon studies unit for the American Academy of Religion and served as co-chair.
[2][8] Having background in Hawaii and Pacific Mormon history, Underwood is a Tour Director for the Hawaiian excursion from the company LDS Travel Study.
[6] The Millenarian World of Early Mormonism Underwood has also written several articles on a broad variety of topics related to the history of the LDS Church, especially related to the doctrinal views of the LDS Church and its members in the nineteenth century.