Born in Delmont, South Dakota. He shortly moved to Orange County, California. He graduated from the University of Michigan in 1919. Employed as a consultant petroleum geologist and registered petroleum engineer. He served as an infantry lieutenant during World War I. Married to Otta with a son and a daughter. Otta died April 6, 1976. He received the Silver Beaver award from the Boy Scouts of America in 1938.

Bergen served as president of the Orange County Coin Club in 1944 and secretary 1947 to 1965. He was president of the California State Numismatic Association 1959 to 1961. Served as ANA second vice president 1961 to 1967; first vice president 1967 to 1969; and as 36th ANA President August 16, 1969, to August 14, 1971.

He was the editor of the ANA Club Bulletin 1961 to 1967. He served on the Assay Commission for 1971. Received ANA Medal of Merit in 1972. He received the ANA Ferran Zerbe Memorial Award in 1974. He was named a Numismatic News Numismatic Ambassador in 1977.

He consigned coins to a Kreisberg & Cohen auction October 4, 1979. In 1982 he was elected to the ANA Numismatic Hall of Fame.

Profile NUM Aug 1961:1054; obit: NUM 102 Feb 1989 page 316