Barry McGuire is the famous baritone on a few of the New Christy Minstrels albums in the early 1960s. He really belts it out on this song, giving it a real wild west flavor.

Randy Sparks ran into him at a bar in Oklahoma and heard him preform, and asked him to join their informal group. Previously, Barry McGuire was a commercial fisherman, and then became a journeyman pipe fitter. His accent was authentic.

https://www.wikiwand.com/en/Barry_McGuire

Over the years, the New Christy Minstrels have had over 200 different members, many of are artists who then went on to own right -- like the Byrds, the Association, Kenny Rogers, etc.

Barry McGuire went on to fame with his song the Eve of Destruction, and eventually became a contemporary christian music singer, after the great born-again Christian movement of the late 60s that many artists became involved in.