At that point it was not clear where Siegel was going with his career—many film directors had entered television without ever returning to feature work—but his next two projects answered that question with authority. The feature Madigan (1968) was arguably the best police procedural of the 1960s, with Richard Widmark providing an acclaimed performance in the title role of a detective searching for a killer; also notable was Fonda as a police commissioner and Inger Stevens as Madigan’s wife. In 1968 Siegel also helmed Coogan’s Bluff, which established Clint Eastwood with American audiences after his years of working overseas with director Sergio Leone on a series of “spaghetti westerns.” In that classic of action filmmaking, Eastwood portrayed a laconic Arizona deputy sent to New York City to extradite an escaped killer. The renegade loner with uncertain morals became a common character in Siegel’s films. For his next project, he replaced Robert Totten on Death of a Gunfighter (1969), which featured Widmark again. However, both Siegel and Totten had their names removed from the film, and it was released with the credit Allen Smithee—the standard pseudonym for work disowned by its director.

Siegel then reunited with Eastwood for a series of movies. Two Mules for Sister Sara (1970) was a rather whimsical western with Eastwood as a cowboy who rescues a prostitute pretending to be a nun (Shirley MacLaine) from three would-be rapists; it was based on a Budd Boetticher story. Next was The Beguiled (1971), an unusual psychological drama set late in the American Civil War. Eastwood played an injured Union soldier whose arrival at a girl’s boarding school in the South leads to tension and ultimately murder. The Gothic film was initially rejected by American audiences, though it proved popular in Europe. Later in 1971, however, moviegoers in the United States turned out in droves for Dirty Harry, which was probably Siegel’s best-known picture (though not necessarily his most admired). It catapulted Eastwood to superstardom as the quintessential antihero of the 1970s; he played Harry Callahan, a tough San Francisco policeman hunting a serial killer. Some critics decried the violence, but Dirty Harry led to four profitable sequels, though none was directed by Siegel.

Siegel next made Charley Varrick (1973), a top-notch thriller with Walter Matthau playing a small-time robber on the run from a hit man after unwittingly stealing Mafia money during a bank heist. Siegel ventured into espionage with The Black Windmill (1974), which starred Michael Caine as a spy whose son is kidnapped. However, the director seemed uneasy with the genre, and the ending was disappointing. Siegel rebounded wth The Shootist (1976), an elegiac western that was the last film made by John Wayne, who played a gunslinger dying of cancer; Wayne would die from cancer-related complications in 1979. The cast—James Stewart, Lauren Bacall, Richard Boone, Hugh O’Brian, and John Carradine, among others—was particularly noteworthy, and some call that film Siegel’s finest achievement. Telefon (1977) was not in the same league, but Siegel (who took over from Peter Hyams) still managed to craft a solid, if complicated, espionage drama, which offered a memorable performance by Charles Bronson as a KGB agent.

Escape from Alcatraz (1979) was stronger, a prime vehicle for Eastwood based on real-life inmate Frank Morris’s 1962 escape from the prison on Alcatraz Island. Although perhaps longer than necessary, the film gains power from its starkness. Siegel’s final two films were box-office failures. In Rough Cut (1980) Burt Reynolds played a suave jewel thief; Siegel was the last of several directors to work on the production. The comedy Jinxed! (1982) featured Bette Midler as a singer who conspires with a blackjack dealer (Ken Wahl) to kill her gambler boyfriend (Rip Torn). Siegel retired thereafter.

Siegel’s autobiography, A Siegel Film (1993), was published after his death. The book’s foreword was written by Eastwood, who regarded Siegel as a mentor. In addition to helping establish him as an iconic actor, Siegel strongly influenced Eastwood’s directorial style.