Eric Bana

On those few welcome occasions when “Untamed” cuts away from its plotline to immerse us in Yosemite National Park, there might be an intake of breath and a sense of cosmic innocence. A place so mutely beautiful could never be despoiled by warped humanity. Right? That’s just what they want you to think.

What is it that attracts criminals to a place as otherwise majestic as Yosemite? “They think no one is watching them,” says Kyle Turner (Eric Bana), a special agent for the National Park Service’s investigative branch. He takes a God’s-eye view of his particular Eden, which is “the size of Rhode Island” and keeps him busy: People disappear, get killed, deal drugs and squat on federal land exercising “constitutional rights” they don’t have. Kyle, who has a drinking problem, the personality of a dental abscess and little patience for anyone, leaves the free spirits alone, unless the body of one comes toppling off El Capitan, gets tangled in a climber’s ropes and shows signs of having been chased, shot and otherwise terrorized.

Rosemarie DeWitt

Despite a title that seems calculated to pitch this six-part drama into the mental dustbin of adjectival crime dramas, “Untamed” is a mystery that this viewer binged with uncharacteristic enthusiasm. And which has a novel premise: Who enforces “human law in nature’s vast wilderness,” as the advertising asks? And does wild nature have any influence on human nature? Not really, other than the bit of cover it provides. Kyle’s well-known alcohol problem stems from the loss, some half-dozen years earlier, of his young son, Caleb (Ezra Wilson, in flashbacks), who was abducted in the park and murdered. He’s also still in love with his ex-wife, Jill (Rosemarie DeWitt), and she with him, their bond of a dead child being both distancing and unbreakable. (Josh Randall, who plays Jill’s new husband, Scott, is never without a grimace of pained confusion.)

Kyle was probably never a warm and fuzzy forest creature, but his lack of personal charm is renowned among his coworkers. Mr. Bana, always pretty great, makes him sympathetic in his consistency, yet open to being won over by the few people he considers competent—his superior, Souter (Sam Neill), for instance. Or, little by little, Naya Vasquez (Lily Santiago), a former L.A. cop who has fled the city and an abusive partner, joined the Park Service, and takes a healthily amused approach to Kyle’s prickliness. She also has a knack for being where she should be in the nick of time.

Sam Neill and Mr. Bana

“Untamed,” created and written by Mark L. Smith and Elle Smith, seems to take a perverse pleasure in poking at certain viewers’ neuroses. The acrophobes among us will be perspiring during the opening moments on the massive El Capitan, where climbers are barely tied in when the body of Lucy Cook (Ezra Franky) comes plummeting past, only to hang up on their line. Naya’s exploration of an abandoned gold mine suspected of being used by drug smugglers will already have the claustrophobes on edge, and then the tunnel fills up with bats. (Heads up, chiroptophobes.) Eclipsing all the other stressors will be Caleb, whose absence haunts the proceedings and resounds in Ms. DeWitt’s heartbreakingly cheerful performance. She’s never been better, and she and Mr. Bana make the kind of couple whose separation makes no sense.

But “Untamed” is a mystery, after all, about multiple murders and no small crowd of suspects. (Or tourists: The series acknowledges, while not belaboring, the crowded state of national parks.) This review has probably been remiss thus far—and distracted by the acting, characters and relationships— in not pointing out how much action and adventure is involved in the story, and how much an Old West ethos and frontier flavor inform the series. Someone refers to Kyle, dismissively, as “Gary Cooper,” but that’s hardly a diss.

Untamed

Thursday, Netflix

Mr. Anderson is the Journal’s TV critic.