For 50 years, they have been the best of friends.

When something significant happens in the life of Gigi Davin, she immediately shares the news with her pal, Kris Grahn. The reverse is also true. Been that way since they were 10-year-old girls.

It is a wonderful friendship, the women say, and with very few exceptions, it has been conducted entirely through the U.S. Postal Service.

“We grew up together through the mail,” says Davin, who lives in Sabattus. “We’ve talked about everything, from the weather to school, our children, our work, our homes. We’ve been in constant contact.”

“We probably know as much about each other as anyone does,” says Grahn, who lives about 1,300 miles away, in Oshkosh, Wisconsin.

The girls became pen pals when they were elementary school students. At the time, Davin was growing up on a dairy farm in Sabattus.

“Our school had the names of other schools and we just picked a name,” she recalls. “They said, if you want a pen pal, you write a letter. If someone writes back, then you have a pen pal.”

Davin sent her letter. A girl named Kris sent one back, and for 50 years that chain has gone unbroken.

“It’s not like we just wrote each other once a year,” Grahn says. “We probably wrote a couple times a month. I don’t think many weeks would ever go by without a letter.”

When the girls graduated from high school, they wrote each other and compared notes. When Grahn went off to college, she wrote to her friend Gigi to tell her all about it.

When each got married, they discussed the exciting news with ink and paper. Same when they had kids. Got jobs. Bought houses and had families.

“I’ve sent her pictures of my grandchildren,” Davin says. “She’s sent me pictures of her and her family. We’ve never missed Christmas presents, birthday gifts or any occasion — even St. Patrick’s Day or the Fourth of July, you name it. And everything has been done through the mail.”

Everything, that is, with one small exception. In 1976, after both girls had graduated high school, Grahn came to Sabattus to visit Davin on the farm.

“Her parents sent here here for a Maine vacation,” Davin recalls. “We were able to take her to a few places, like Popham Beach and Camden. She had never seen the ocean.

“She was excited to see the water and the beaches. I remember she was amazed at how many hills we have here, because Wisconsin is very flat.”

For some, a face-to-face meeting might end the era of pens and paper, stamps and envelopes. But not for Davin and Grahn. As soon as that visit was over, they went right back to letter writing and for 42 years, they never saw each other again.

But that changed on Thursday when Davin made her way to the airport in Portland to pick up her lifelong friend. From there, the pair headed to the boat known as The Cat, which would ferry them to Nova Scotia.

For the first time in more than four decades Davin and Grahn would occupy the same physical space. They would see each other and vocalize their thoughts instead of jotting them down.

Why meet after all those years of distance?

“We both turned 60 this year,” Grahn says. “We just thought it was time to do something about it.”

It is not that they have not tried to meet. In 2009, Davin’s and Grahn’ families planned to hook up during vacations in Alaska. Last-minute snags thwarted those plans, however, and until this year, it was back to writing letters.

The idea to go to Nova Scotia came up during a routine conversation.

“I had mentioned to her that my passport runs out in 2019,” Davin says. “I said, ‘I’d like to go to Nova Scotia.’ She said, ‘Hey, I’d like to go there, too.’ We’ve been talking about it for the past two years, and we’ve been planning it since March. Now, here we are, going to Nova Scotia.”

How did such an enduring friendship blossom through letters?

Maybe it is because they have a lot in common. When they became pen pals, both were 10-year-olds living in relatively rural parts of the country. Both are also artists who had sent one another paintings and other artwork.

Davin believes the friendship flourished not in spite of its confinement to the written word but because of it.

“When you write a letter, you can get into more detail,” she says. “It’s almost been like a ‘Dear Diary’ kind of thing.”

The friends prefer letters, for sure, but as they were planning the Nova Scotia trip, they cheated a little by occasionally using text messages and email to plan the trip. It is not a trend they expect to last.

If it ain’t broke, after all, why fix it?

“I’m sure once the trip is over,” Grahn says, “we’ll go right back to writing letters.”