The first rule a Western fan applies to any modern take on the genre is the eyeball test.

“Butcher’s Crossing,” a lean, gritty parable about shortsighted greed and environmental destruction, looks right. Not original “True Grit” celluloid cinematic, but “Lonesome Dove” authentic, with sweeping vistas, herds of buffalo and a star — Nicolas Cage –– who looks at home in the saddle and scary in his mania for bison hides.

Director and co-writer Gabe Polsky (“The Motel Life”), adapting a John Williams novel, gets good value from his lead, his supporting players and his Montana locations in a film that makes up for its somber pacing and downbeat subject with its fascination for details.

Fred Hechinger of Netflix’s “Fear Street” movies stars as Will, a Unitarian pastor’s son and Harvard boy from “back East” who quit school in search of “stronger purpose and meaning in my life.” The greenhorn has made his way West, to Butcher’s Crossing, Kansas.

It’s 1874, and for a naive lad with designs on “seeing the country” and experiencing the Frontier, he’s found it. Butcher’s Crossing is where the buffalo hunters roam.

Will looks for guidance from a man his preacher-father once took in. But McDonald (Paul Raci, irrascible and fun), who trades in buffalo skins to be turned into the warmest fur coats of their era, is full of warnings and depradations. No, boy, you DON’T want to go hunting.

“It’ll ruin you. It’ll get in you.”

That Miller fellow (Cage) down at the saloon fits the iconic image of a buffalo hunter. Bearded and broad, bald and wrapped in a buffalo robe, he’s as dismissive as McDonald was cautionary.

“Ain’y no ‘tours’ around here.” But if the lad would care to underwrite an outing, the somewhat disreputable Miller knows of a valley where the herd hasn’t been thinned, way off in Colorado.

Finding men to ride with them isn’t all that hard. Old cookie Charlie (veteran character player Xander Berkeley, instantly credible) is Miller’s superstitious, tippling sidekick, ready to drive the wagon. The skinner Fred (Jeremy Bobb of TV’s “Russian Doll” and “Godless”) is another matter. He’s a skeptic.

Miller, it seems, is a big talker whom some have taken for a crank. Chatty, bickering Fred will take a flat fee, thanks. None of this “share the take” risk for him.

They set off through “Indian country” to find the mother lode of buffalo herds. And once there, Will starts to figure out what McDonald’s warnings and Fred’s doubts were about.

The script leans into some tropes of the genre — Will’s pursuit by the saloon’s resident sex worker (Rachel Keller) and dodges others. “Indian country” isn’t particularly perilous.

Cage doesn’t go full NIC CAGE in this role, playing a man more interested in a bragging-rights take to silence his doubters back in Butcher’s Crossing than in settling some darker psychic score. The threat of violence is more subtle, Miller’s monomania is expressed in smaller, meaner ways — refusing to help a stranded widow and her two boys who lost their wagon train.

Polsky focuses on the how-to’s of buffalo hunting as we watch Miller shave his head, load his own rounds and lay out the ways to pick off the herd without scattering it. It’s heartless work, and to Will, starts to seem heedless.

“We’ve got enough,” he insists. “No sense shooting more than we can skin.”

Some old fashioned Cage mania might be appropriate here. Perhaps the John Wayne as Ethan Edwards rationalization from “The Searchers” — killing buffalo to starve out the Natives — might have given this unslakeable thirst for wiping a herd out more meaning.

Bobb adds value as the voice of experience and doubt. Berkeley’s superstitious Charlie gives us just enough (barely) of a “deliver us from evil” message. And Hechinger’s journey from naive to experienced enough to have doubts is adequate, if little more.

But the big setting, big themes and big star’s subtle turn as a blowhard more misguided than manic are enough to put this Western over.

What few real tests the young man from Back East must face, the picture about his coming of age passes the most important. It looks and feels right, with buffal-in-their-element scenes that don’t have the scale of “Dances With Wolves,” but play big enough to make the parable’s point land and land hard.

Rating: R for language, some violence/bloody images and brief sexual content

Cast: Nicolas Cage, Fred Hechinger, Jeremy Bobb, Rachel Keller, Xander Berkeley and Paul Raci

Credits: Directed by Gabe Polsky, scripted by Gabe Polsky and Liam Satre-Meloy, based on a John Williams novel. A Saban Films release.

Running time: 1:48