On a sunny day, after touring the Gene Autry Western Heritage Museum, Selleck, dressed in a black long-sleeved polo shirt, jeans and boots, speaks of his fascination with history.
He discusses giving some memorabilia from his Westerns with museum curators, admires a wall dedicated to Western heroes, such as John Wayne and Roy Rogers, and graciously shakes hands with adult fans who pop by to reminisce about their affection for Magnum P.I.
"With the Industrial Revolution and mechanical inventions and the progress that was going on, and the unlimited frontiers, I would have liked to live in the 1890s," he says.
"I always found history pretty interesting ... If you get a good history teacher, it makes it come alive. You learn an awful lot about human nature, and the predictableness of it, by looking at the past."
The allure of the past has made Selleck (66) a stickler for authenticity in his movies.
"I've done quite a few Westerns, and as I started getting involved in the productions, I realised I've seen a lot of Westerns where the props and wardrobe weren't accurate," he says. "You'd see somebody with a saddle that was clearly a 1950s saddle and it was set in 1890. So I started making my own saddles."
Ditto with firearms, he says.
"You'll see a Western that takes place in 1860 and they're using firearms that weren't invented till 1890. So I started building a lot of that stuff into my movies, and audiences seem to really like the accuracy."
Selleck is a member of the National Rifle Association board of directors and has donated rifles he used in movies for NRA exhibits.
Selleck has made more than 50 movies for television and the big screen over the course of his career, but he visibly relishes talking about the Jesse Stone movies.
"I'm very proud of this franchise," he says. "I don't think there's been a successful character recurring in TV movies since Columbo. I think we're in the same ball park."
The films have a moody sense of mystery, each directed by Robert Harmon and starring many of the same actors.
Police Chief Stone is a melancholy loner, a bit beaten down, still hung up on his ex-wife and also somewhat of a Luddite. His drink of choice is Scotch, and he believes his soulful-looking dog is his conscience.
CBS has approached Selleck about turning the movies into a television series, but Selleck remains dubious.
"The storytelling would have to change," he says. "It's hard to abbreviate a two-hour movie into a one-hour series. We don't speak shorthand. At this point I feel a certain loyalty to the character and to the audience."
Selleck is a big believer in taking risks. He cites his three biggest: starring in his first Broadway show (A Thousand Clowns in 2001) at the mature age of 56, portraying Dwight D. Eisenhower in the 2004 TV movie Ike: Countdown to D-Day and taking three years off from acting in the 1990s.
There's only one movie he speaks ill of: 1992's Christopher Columbus: The Discovery.
"I got offered this movie to play Ferdinand, king of all Spain," he says, laughing. "I was only in it for like five scenes, but Marlon Brando was in it, and I did it to work with him."
He goes on to say: "It was a horrible movie. Gene Siskel hated it and reviewed my wig. But I got to know Marlon Brando. That was cool. But the movie was not cool."
The experience prompted him to take time off.
"It was going to be a year off, but it turned into three," he says.
During the break he spent time with his family on his 60-acre ranch and worked with charities.
"Everyone thought it was because nobody was offering me any work," he says.
No-one could make that accusation today. Selleck is contemplative, knows himself, what he likes and his strong points.
When the subject of his age comes up, he cites a personal hero: Sean Connery.
"Connery always said, 'You've just got to be comfortable in your own skin'. You've got to know what you can and can't do."
Selleck is eager to show what he can do.
"Any good part should scare you," he says. "It's the price you pay for opportunity. That doesn't mean I've been good in every part I've ever done, or that you should do something just to prove you can.
"But you should be scared.
Otherwise you get smug. Long careers are rare. If you take the people who like your work for granted, I believe you will never get them back."
• Jesse Stone: Night Passage screens tonight at 8.30pm on Vibe.
