Bonanza actor Pernell Roberts died of cancer on Sunday at his Malibu home, his wife Eleanor Criswell told the Los Angeles Times. Pernell was 81 years old and he was the last surviving member of the Bonanza cast. He rocketed to fame in 1959 as Adam Cartwright, eldest son of a Nevada ranching family led by Lorne Greene’s patriarchal Ben Cartwright. He left the show at the height of its popularity because of limitations he felt his character was given. He later found fame again on Trapper John MD.