Slim completed two years of high school, at which time he became a professional musician at the age of 15 in 1932 - however, he was performing at grange halls and fairs as early as 1930.
In 1936, he went on the air as "Wyoming Buck" and a few months later the radio station manager renamed him "Yodeling Slim Clark" - which was his trademark throughout his career.
His performances at WKNE starting in 1938 included a weekly show with Keene announcer Ozzie Wade.
Though primarily known as a single act, Slim's bands included the "Red River Rangers",[3] "The Trailriders" and "The Trailsmen".
Country music favorites Kenny Roberts[3] and Dick Curless (The Tumbleweed Kid) were members of the Red River Rangers and the Trailriders, respectively.
In 1946, Slim signed with Continental Records in New York City, at the urging of yodeler Elton Britt.
He gained popularity throughout the United States, Canada, Australia, New Zealand, and Europe with only a handful of appearances outside his lifelong New England base.
During his younger days, Slim played pro-baseball as a pitcher for the Blackstone Valley League in Massachusetts.
In addition to sports, he maintained a lifelong interest in hunting and fishing, as well as farming and was a Registered Guide in Maine, Massachusetts, New Hampshire and Vermont for over 17 years.