Tom Selleck is 79 and, whew, just look at this magnificent specimen

Selleck purchased the ranch, which used to belong to Dean Martin, in 1988 and has maintained it with proceeds made from a half-century of playing big men on the small screen: “Magnum, P.I.” in the ’80s, an arc on “Friends” in the ’90s, now the long-running CBS show “Blue Bloods,” on since 2010.

The ranch is Selleck’s refuge from red carpets and other settings where people look him in the mustache instead of the eyes, and ask the same questions over and over. (Who is he wearing? He’s wearing no one. He’s wearing a tux. The one he bought. C’mon.)

He wakes up and feeds four dogs, four sheep, two cows and a few horses. Selleck himself plants the oak trees, now more than 500 of them.

“My back knows how many.”

He points to a young oak with a creeping dark coloration crawling up one side of its trunk.

“This one’s a little sick, and I really care about it. I planted that for my dad, and he pruned it.”

He flips the ATV’s engine back on and drives, crunching gravel as whiptail lizards scamper, until he reaches the ranch’s summit. Overlooking the valleys is a gazebo from the Halifax, Nova Scotia, set of the first of nine TV movies in which he portrayed yet another officer of the law: alcoholic detective Jesse Stone.

The first thing you notice, upon meeting him, isn’t the mustache. It’s his height: a towering 6-foot-4. On a warm spring day, he wears loose blue jeans, a red checkered shirt and a tweed vest.

At 79, he’s assumed a grandfatherly air. His stories are infused with nostalgia and introspection. He often breaks into mirthful laughter. His dimples form, and you can see the young heartthrob his friend Ted Danson calls “a magnificent specimen of a man.”

Selleck is fond of aphorisms and mantras, both in writing and conversation.

“Keep laying bricks.”

“Always expect the expected.”

And the line from his 1990 western “Quigley Down Under” that he wanted as the memoir’s title: “Don’t know where I’m goin’, but there’s no use bein’ late.”

Reading his memoir feels an awful lot like chatting with him in the 114-year-old hunting lodge on his ranch, decorated with a stuffed owl and a painting of the director John Ford, who made 14 films with John Wayne — the kind of westerns that Selleck would make in film and TV. Selleck wrote his memoir on lined yellow pads with the guidance of columnist Ellis Henican.

“You’re the first male I’ve encountered who read it,” he tells me, with delight. The foundation of his career, like Wayne’s before him, was his masculinity, his sheer size, his simple coolness, that bygone allure: Women wanted to be with him, and men wanted to be him.

“He is an old-fashioned — in the best sense of the word — gentleman,” says Danson, who co-starred in Selleck’s only bona fide hit on the big screen, “Three Men and a Baby.” Danson adds, “He is that perfect western hero, the embodiment of that old Gary Cooper leading man.”

Selleck is a private person, particularly about his politics. He was briefly an unpaid board member of the National Rifle Association but has made it clear that he was never its spokesman. He has made minimal donations to candidates on either side of the aisle.

“He is honorable, honest, bright, caring and conservative,” Danson says. “I’ve always respected him hugely, even though we are a little on other ends of the spectrum politically.”

The closest Selleck will get to politics is ruminating on what’s “eating the country alive”: “Everybody’s looking for a chance to get angry, to be offended. It’s a choice. … And frankly, that’s not the American compact. The American compact is we agree to disagree.”

He’s even more private about his personal life, which made crafting a memoir challenging.

“I didn’t do the book to set the record straight,” Selleck says. “I didn’t do the book to settle scores. I didn’t at all want to make it a political book, and I didn’t want to talk about who I was dating.”

About half the memoir focuses on his failure to hit it big before 35. There are a few celebrity stories — one features an impatient Frank Sinatra, at the end of his acting career, demanding Jack Daniel’s and wearing a colostomy bag on the set of “Magnum, P.I.” — and a few soft complaints about various strikes by the Screen Actors Guild.

The book ends with the “Magnum, P.I.” finale in 1988 — leaving about half of his life (and all of his mustache!) unremembered.

He just started writing one day, got about 200 pages in, and realized it was still the 1980s.

“I had no plan,” he says.

Of course he didn’t have a plan. He rarely did, even before he got famous. As he’s fond of saying: He didn’t know where he was going, but there’s no use being late.

But when you’re that goddamn handsome, who needs a plan? He floundered at the University of Southern California, which he attended on a basketball scholarship. The only reason he’s an actor is because he took a theater history class for an easy A, and the teacher introduced him to an agent, who in the mid-1960s got him commercial work for the Air Force and for Pepsi. Then toothpaste, soap, auto parts, Schlitz beer. He went on “The Dating Game” with some frat buddies on a whim — Bachelor No. 2 “plans to enter the world of business” — and caught the eye of a casting director at Twentieth Century Fox.

Suddenly, he was in Fox’s new-talent program, with another young actor who could also grow a helluva mustache: Sam Elliott. Their peers’ reaction to Selleck at the time, Elliott says, was, “How could such a nice guy be so impossibly handsome?”

In 1967, Selleck received a draft-physical notice, which might have concerned someone with a plan. But Selleck rolled with it and joined the California Army National Guard, serving for six years but never seeing Vietnam.

The talent program shut down, which might have concerned someone with a plan. But he was handsome and kept working, in small roles like “stud” and “deputy.”

He caught the eye of Mae West, who objectified him in “Myra Breckinridge” (1970) and compared him to Cary Grant in the press.

But a Grant-like movie career wasn’t materializing. Selleck appeared in “Daughters of Satan,” a schlocky horror movie. He made six pilots, but none went to series. Every opportunity seemed to fizzle. Luckily, he says, he had “an appetite for failure,” developed through a losing sports career.

He kept laying bricks. An episode of “Mannix.” Brick.

An episode of “Charlie’s Angels.” Brick.

Two episodes of “The Rockford Files.” Brick, brick.

He became Thomas Magnum, private investigator, in 1980. He was 35 and had grown into his rugged handsomeness. After years of stagflation and a crisis of confidence, America was ready to cruise down a beachside highway in a bright-red Ferrari. It was also ready to reckon with Vietnam on prime-time TV. “Magnum, P.I.” managed to blend both sensations.

The hour-long CBS drama followed a Vietnam vet who quits the Navy to live as a P.I. in Hawaii because, as the character says, “I woke up one day, age 33, and realized I’d never been 23.”

Selleck is immensely proud of the show, partially because he helped shape it. This time, he had a plan.

The original pilot script, written by Glen Larson, portrayed Magnum as an American James Bond: a flawless, smooth, Ferrari-owning ladies man who came out of every fight unscathed. Selleck despised it. He wanted to play a flawed character. He wanted the show to entertain but also have something to say about the world. He said he would consider the show only if Larson (who died in 2014) wasn’t involved — and if they got a new pilot script.

Donald P. Bellisario took over and wrote a script in which Magnum lives in the guesthouse of a famous writer, for whom he provides security detail. Magnum “borrows” the writer’s Ferrari from time to time. And he’s besieged by harrowing flashbacks to war.

The network didn’t want Vietnam to be part of the show. But Selleck and Bellisario pushed back hard. For Selleck, the opportunity cost of making the show was immense, because he was offered another role at the same time: Indiana Jones in “Raiders of the Lost Ark.”

Back then, stars didn’t switch between the big and small screens. Bob Daly, the head of CBS, wanted Selleck to be his TV star and said that he couldn’t do both roles.

Was that Tom Selleck’s path to Cary Granthood, or to a movie career like Harrison Ford’s? We’ll never know. But “Magnum, P.I.” was a hit. Selleck remains proud that it “positively” depicted a Vietnam vet beyond the violence, trauma and cynicism that American moviegoers had seen in the two years prior, with “The Deer Hunter” and “Apocalypse Now.”

His character’s iconic Hawaiian shirt, Detroit Tigers cap and signet ring were later acquired by the National Museum of American History. For a while, though — living and working 14-hour days in Hawaii — Selleck didn’t quite know how famous he was. He learned on the Golden Globes red carpet in Los Angeles, where he drowned in flashbulbs and felt suffocated by reporters’ questions, which veered from the overly personal (“How’s your love life?”) to the highly inane (“Who are you wearing?”)

Selleck claims that fame doesn’t really work for him. He hated how the tabloids hounded him about his romantic life.

With fame, “it’s a question, then, of what can you hold sacred?” he says. “What small part of you can you keep to yourself and those you care about?”

His upper lip is a small part of him, but he can’t keep that to himself. The mustache belongs to the world. It lends him the authority to portray a police commissioner, and perhaps to sell you a reverse mortgage (as a spokesman for American Advisors Group).

And like much of his career, the mustache was unplanned. He wore one in “Magnum” simply because it was in style then.

“It wasn’t because Burt Reynolds had one,” Selleck says, “though I think Burt thought it was.”

Conan O’Brien, he says, made it funny. In one appearance on O’Brien’s late-night show, Selleck shaved off half his mustache so he could believably promote a TV movie in which he played the always clean-shaven President Dwight D. Eisenhower. In another appearance, O’Brien walked Selleck to a miniature hospital to visit his sick mustache in a little bed. Selleck smothered it with a tiny pillow — the closest he could get to killing off his own stereotype.

His bare upper lip took the blame when his 1992 movie “Folks!” flopped.

“I didn’t have a mustache,” he says. And the producers said, “‘It’s the mustache! That’s why it didn’t make any money!’”

When CBS came knocking again, with “Blue Bloods” in 2010, Selleck thought that a mustache might not fit his character. The network didn’t care. The mustache was nonnegotiable.

Everything about Selleck harks back to a bygone era: the fierce desire for privacy. The unspoken politics. The mustache, yes. And, most notably, the career itself. It is nearly impossible to imagine anyone reaching Selleck’s level of fame primarily through television today.

“Gen Z-ers, well, they don’t know who I am,” he says. Everyone else recognizes him from “Friends,” “Blue Bloods,” the Jesse Stone films and “Magnum.” And maybe “Three Men and a Baby.”

“Blue Bloods,” a procedural about a multigenerational Irish American family that works in New York law enforcement, is ending after 14 seasons and 293 episodes — 131 more than “Magnum.” The crux of each episode is a family dinner where they talk and argue about work. Much as “Magnum” used its shiny surface to sneak Vietnam into prime time, “Blue Bloods” occasionally attempts to process, through scenes of family drama, America’s fraught relationship to law and order.

Selleck isn’t ready for the show to end. He doesn’t want to fully surrender network TV — which Americans used to gather around en masse and which gave him bricks for building a career — to streaming services, where the audience is atomized, and which might not accommodate Tom Selleck in twilight.

But out here on his ranch, he doesn’t have to think about all that, if he doesn’t want to. He doesn’t have to think about being famous, or about who he’s wearing, or about contracts, or ratings, or what happens when you stop laying bricks.

“I have a lot of a trees to watch,” Tom Selleck says.

And if he wants to shave the mustache out here, he damn well can. His trees won’t complain.