Ralph Waite, a multifaceted actor who became etched in television history as the craggy-faced, big-hearted patriarch of a rustic Depression-era clan on the popular 1970s dramatic series “The Waltons,” died on Thursday at his home in Palm Desert, Calif. He was 85.

His death was confirmed by Susan Zachary, his agent, who said the cause had not been determined.

Mr. Waite was a respected New York stage actor when he was offered a role on “The Waltons,” and at first he was not enthusiastic about it. But his agent, he recalled, advised him to take the part so that he could “pick up a couple of bucks” in Hollywood and go back to New York.

“The Waltons” made its debut on CBS in September 1972 against two already popular shows: Flip Wilson’s irreverent comedy-variety show on NBC and, on ABC, “Mod Squad,” a drama about young undercover police officers. What some saw as a cornball newcomer was expected to be buried, but within two seasons it had driven its competitors off the air.

The success of “The Waltons” owed much to the actors and the characters they played, members of a homespun rural family used to surmounting challenges through old-fashioned virtues. The foremost was John Jr., known as John-Boy, the oldest of seven children. Played by Richard Thomas, he was a serious young man with a passion to be a writer.