Complex sentence: The U.S. Forest Service achieved widespread awareness during the 1960s, as it became the setting for the long running classic TV show "Lassie" with story lines focusing on Lassie's adventures with various forest rangers.
Split into simpler sentences: The U.S. Forest Service achieved widespread awareness during the 1960s. It was the setting for the long running classic TV show "Lassie" with story lines focusing on Lassie's adventures with various forest rangers.