Sam Elliott knows how to grip a screen. That rumbling basso voice. That gigantic caterpillar mustache. That low-key attitude. Put him up beside the star of  “The Big Lebowski” in a two-minute cameo, and Elliott puts the film right in his pocket.

He has worked steadily in film since he ambled into the industry in the 1969 western “Butch Cassidy and the Sundance Kid.” It was smaller than a bit part, a mere extra speaking three words at a card table: “I’ll take two.” People haven’t been able to get enough of him since, including Katharine Ross, the female lead of “Butch Cassidy,” who became his wife. The man has appeal.

Now Elliott does some of his finest work in one of the best movies in his career, a drama that feels like a biography. In “The Hero” Elliott plays a character much like himself, but less lucky in his career.

He’s veteran actor Lee Hayden. He’s 71, been absent from the movie world for decades and doing occasional work as a voice-over announcer for ads. To be a onetime western icon reduced to repeating into a microphone “Lone Star bar-ba-cue sauce, the perfect pardner for yer chicken” naturally produces a bit of melancholy. He’s an artifact of a bygone age. When we see Lee in moments of costumed cowboy spectacle, they are his dreamlike fantasies.

They’re better than his reality, as revelation after revelation discloses serious health and family issues. When he receives word that a western film fan society wants to honor him with a lifetime achievement award, he repeats “lifetime” with a sardonic chuckle, quietly considering what he has achieved. His rare meetings with his unloving ex-wife (Ross, who I hope treats him better in real life) are painfully strained. His contact with his adult daughter (Krysten Ritter) is nonexistent. For important reasons, he wants to reopen those blockades while he still can. After all, the brief contacts list on his smartphone doesn’t occupy the whole of its little screen.

It may mean a new lease on life when he meets intelligent, poetry-loving Charlotte (Laura Prepon of “Orange Is the New Black”). Or it might pull him into a wrong turn on his life’s journey. A performer herself, she meets Lee at the home of his former co-star and current drug dealer Jeremy (Nick Offerman in mischievous form, repeatedly explaining why life is an iceberg). Charlotte finds Lee alluring despite their vast age gap, a sort of personal drama that Lee doesn’t need right now. He isn’t chasing the role of Lothario.

There’s not much story here, but I didn’t feel that there needs to be. Sometimes a bit less is enough. Despite a few minor discrepancies, the writing is civilized, serious, reasonably sentimental and occasionally amusing. The characters, especially Lee, hold our interest. Elliott builds this isolated man in his own minimalist acting style. He creates through hushed moments of lacerating distress feelings that overwrought proclamations of agony would ruin. Even in scenes of him watching the Malibu surf and silently pondering his past and future, he’s sublime.

Keeping things credible and simple but not simple-minded has always been Elliott’s stock in trade. It’s great to see him finally on center stage, holding the spotlight in a show all his own, America’s oldest rising star.