Three members of the bass section of the Big Rapids High School A Capella Choir formed a folk trio, The Coronados. The name of the group had no inherent meaning; it just sounded cool to the members.
George Dunn sang lead and played guitar; Glen Newton sang tenor harmony and also played guitar; and John King sang baritone harmony and played banjo. They competed in the Big Rapids Optimist's Club talent contest in 1964 and won first place.
Adding Darlene Thorstenson to the group for a performance at a school dance, they became The Coronados Plus One. For that performance, John switched to string bass, and Glen alternated between banjo and guitar. Darlene sang some of the tenor harmonies, so Glen and John often sang baritone and bass.