Described by "TIME" in 1959 as "probably the best horseman on television", for most of his career, Robertson played in western films and television shows—well over 60 titles in all. "Tales of Wells Fargo", his best-remembered series, aired on NBC from 1957 to 1961, when it moved to ABC and expanded to an hour-long program for its final season in 1961–1962. The show originally was produced by Nat Holt whom Robertson felt he owed his career to for giving him his first leading roles. Robertson also did the narration for "Tales of Wells Fargo" through which he often presented his own commentary on matters of law, morality, and common sense. He was unique among his television contemporaries, stating that he hated the gun he was forced to carry, but saw it as a necessary evil, a "tool of the trade", and kept practicing. In its cover story on television westerns, published March 30, 1959, "Time" reported Robertson was 6 feet tall, weighed 180 pounds, and measured 42-34-34. He sometimes made use of his physique in "beefcake" scenes, such as one in 1952's "Return of the Texan" where he is seen bare-chested and sweaty, repairing a fence.