Ellefson is from Myrtle Creek, Oregon and is the youngest son of music educator, Wendell Ellefson (deceased 1994). A 1980 graduate of South Umpqua High School, Ellefson attended and graduated with honors in 1984, from Linfield College in McMinnville, Oregon, where he was honored as the Most Outstanding Alumni of 2012. He received his master's degree in 1985 from Northwestern University. His primary teachers have been Warren Baker, Mark Lawrence, Frank Crisafulli, M. Dee Stewart and Joseph Alessi.
^"EWU recital Wednesday", Weekend magazine published in The Spokesman-Review and Spokane Chronicle, Spokane, Washington, January 11, 1991, page 5. (subscription required)