Rob O'Gara #46 of the New York Rangers skates against...

Rob O'Gara #46 of the New York Rangers skates against the Minnesota Wild at Madison Square Garden on Friday, Feb. 23, 2018 in New York City. Credit: Jim McIsaac

Rob O’Gara has made himself quite at home in the Rangers locker room in the six weeks since he was acquired from the Bruins in the trade that sent away Nick Holden. But if he hadn’t made the decision as a teenager to leave Long Island and go to prep school in Boston, O’Gara is not sure he would have gotten there.

“I had never talked to a college scout, pro scout, or anyone, on Long Island,’’ the rookie defenseman from Nesconset told Newsday recently. “But when I went to Milton (Academy), you played in a fall league, before the prep season starts. And my third game there, the coach was coming to the bench, saying, ‘Yeah, that’s the Dallas Stars scout. He’s here to watch you.’ I was like, ‘ What?’’’

Prep school alone didn’t get O’Gara a ticket to the NHL. His size (6-4, 207 pounds), skating ability, smarts and work ethic are what made him a prospect. But it’s tough for prospects on Long Island, or anywhere in the New York Metropolitan Area, to get seen and taken seriously by college or pro scouts. Prep school is one way to get seen.

Though it can be an expensive one.

Milton Academy, where O’Gara went after leaving Smithtown East just before his senior year, has an annual tuition of $47,330 for day students, $57,650 for boarding students, according to the school’s website. It does have a generous endowment of more than $250 million, according to Wikipedia, and offers need-based financial aid to students.

“There’s no scholarships; there’s no merit money at Milton,’’ Paul Cannata, the school’s hockey coach, said. “But there is financial aid. So, if your father is a venture capitalist, you could be the best player on the team — you’re going to pay full tuition. If your family grosses $200,000 and they live in Northern New Jersey, you’re going to get a pretty good financial aid package.’’

O’Gara said the financial aid he received from Milton allowed him to attend the school for essentially what it would have cost him to play club hockey. And that was the only way his family could afford it, he said.

O’Gara wasn’t the only Long Islander at Milton. Defenseman Pat McNally, a Glen Head native, and goaltender Sean Dougherty, from Smithtown, were teammates. McNally would go on to play at Harvard, was drafted by Vancouver and now is playing in Sweden. Dougherty would play college hockey at Div. III Williams College.

Prep school is a thing in New England, and it’s certainly a thing for hockey players. On the Rangers, besides O’Gara, Chris Kreider, Kevin Hayes, Jimmy Vesey and Kevin Shattenkirk, who is from New Rochelle, N.Y., all went to New England prep schools.

“That New England corridor there, there’s a bunch of teams, like Avon (Old Farms, in Connecticut),’’ said Kreider, who is from Boxford, Massachusetts, and went to Phillips Academy in Andover, Massachusetts. “Cam Atkinson (of the Columbus Blue Jackets) went to Avon. Jon Quick, on LA, went to Avon.’’

Rangers great Brian Leetch, who grew up in Connecticut, also went to Avon.

O’Gara, though, never had any intention of going the prep school route. He was happy at Smithtown East, playing club hockey with the Long Island Royals and wasn’t planning on going anywhere.

In the fall of 2008, his sophomore year, his club team went up to Boston for a tournament, and there he caught the eye of Cannata, who was intrigued by the tall, lanky defenseman. The coach reached out to O’Gara’s father, Brian, who was helping out with the team administration, and asked if the family would be interested in Rob going to prep school. The family considered it, but eventually decided no.

But little more than a year later, O’Gara was back in Boston, this time in July, for a summer tournament. And it just so happened that Milton needed a defenseman. So Cannata came at the O’Garas again, and this time, they decided to go for it.

“I was doing my summer reading for Smithtown East,’’ O’Gara said. “I was getting ready for my senior year. And by the end of August, it was like, ‘Alright, I’m going to repeat my junior year. I’m going to try this. I think this is the best road if I’m going to play hockey in college.’’’

At Milton, O’Gara lived in a dormitory, where he says he met the guys who are his best friends today. Academically, because he was repeating junior year, he found the work to be relatively easy, and on the ice, the team won the New England championship in his first year. O’Gara committed in December of 2010 to play hockey at Yale, and the next summer he was drafted by the Boston Bruins, who traded him to the Rangers Feb. 20, along with a third round pick, for Holden.

“It turned out to be the best decision of my life,’’ O’Gara said of going to prep school. “I’m very lucky that those pieces fell in place, or I don’t think I’d be here (with the Rangers).’’

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