Although proposals for a junior college in southern Idaho were made as early as 1952 and courses were offered at the short-lived Southern Idaho College in Buhl in the early 1960s, it wasn't until the Idaho Legislature passed and Gov. Robert E. Smylie signed the Junior College Act in 1963 that the foundation of what became the College of Southern Idaho began in earnest. In November 1964 voters in Twin Falls County formed a junior college district under the provisions of the Junior College Act. Neighboring Jerome County joined the district in 1965. CSI held its first classes at Twin Falls High School later that year.