The Lewis & Clarke Expedition was a 1960s American folk-pop band, known for their harmonized vocals and acoustic sound. The band included notable members Michael Martin Murphey and Boomer Castleman, both of whom went on to successful solo careers. Though short-lived, the group's significance lies in their innovative blending of folk and pop genres, as exemplified in their influential album "Earth, Air, Fire & Water". Their music was characterized by lyrical storytelling, a popular element of the folk tradition, combined with the catchy melodies of pop music.