Arguably the best vocal group of the popular folk revival of the late 1950s through the mid 1960s was the Chad Mitchell Trio. Each member of the group - Chad Mitchell, Mike Kobluk, and Joe Frazier - was a formally trained singer with chorale/vocal experience prior to their assembling as a trio. They received the most notice for their trenchant satirical and political songs, and for introducing the compositions of songwriter Tom Paxton to a wide audience. But the CMT also had a wonderful way with traditional folk material, as this rendition of the Woody Guthrie classic set to "Wildwood Flower" stirringly attests. Kobluk, Mitchell, and Frazier still do concerts and recordings as of 2009, one of the few groups from that era that still performs with its original members.

A complete discussion of the song with other recorded versions appears in the blog associated with this YT channel, Comparative Video 101, here:

http://compvid101.blogspot.com/2009/01/what-were-their-names-woody-guthries.html