For about seven years, Stan and Sheila Olson of Turtle Lake, N.D., looked forward to periodic postcards from around the world, personal, upbeat and signed, simply, "Jim."

And for about seven years, Stan and Sheila Olson welcomed those breezy updates with the same question:

Who's Jim?

Was he someone they met on a motorcycle adventure? A high school classmate? That long-lost cousin at the family reunion?

They could have racked their brains forever. But when Jim died Jan. 3, the mystery was solved. The Olsons are still laughing at the back story, which Jim's family said is how Jim would have wanted it.

Jim was Jim Moore of Mankato, a playful prankster, keen observer of the human condition and lover of letters -- the old-fashioned kind that arrived in the mailbox with a stamp.

Frustrated that hardly anybody corresponded that way anymore, Moore decided he'd be a one-man philatelic Phoenix. With the assistance of the Internet (a bit of an ironic twist), he randomly picked a prototypical Upper Midwestern town (Turtle Lake, population 581), then a prototypical Upper Midwestern name to go with it: Olson.

About three times a year, Moore penned postcards to the Olsons on his trips to Arizona, New England or as far away as Ireland, specific enough, and vague enough, to have them scratching their heads.

"It's raining today, so I don't know that I'm going to leave right away. I might spend an extra day here. Jim."

"Hoping to go sailing tomorrow if the old leg isn't bothering me too much. Jim."

"Was in Paris and saw Francois and Emilie. They send their regards. Jim."

"He wrote like he knew us. That was what was so funny," said Sheila Olson, 52, bursting into giggles several times during a phone interview. Previously active with Stan in the Gold Wing Road Riders Association, she said her two teenagers were convinced "it had to be someone we met along the way."

Along the way, the whole Olson clan, including Sheila's parents, in-laws and sisters, jumped on the Jim bandwagon, eagerly awaiting the next postcard.

"Our kids have grown up with this," Sheila said. "Whoever Jim is," they all agreed, "we must have really done something to impress him!"

Moore always was a character, said his sister, Susan Moore, 33, a graphic designer who lives in Phoenix. "The first time he'd meet people, he'd observe. The second time, he'd start joking and kidding around with them."

The siblings grew up in Keewatin, just outside of Hibbing, where their mother, Darla, still lives. As a teenager, Moore and a friend carried around a huge video camera, staging gunfights in alleys or filming people walking around town, Susan recalled.

Sometimes, the two friends would attend City Council meetings "because they were bored," Susan said. "There's nothing to do in Keewatin."

Jim got into trouble only once and purely by accident. "He walked through wet cement," Susan said. Standing 6-feet-3 from his early teens, "they knew exactly who it was." Who else would have left a size-13 footprint?

The police came to the house to talk with his parents, who then told Jim: "Be careful where you're walking."

During his first year of junior college, Moore invented "an imaginary friend" with a Groucho Marx nose and glasses, a drill sergeant cap and hunting boots. "They'd prop him up in the dining room drinking coffee," Susan said, "or sit him on the toilet."

Susan heard all about the postcard project, too, which now carries greater poignancy. Her brother, mobile support coordinator for the American Red Cross, was diagnosed with bile duct cancer about a year ago. "Right up to November, he was very positive that he was going to beat it," Susan said.

As he weakened, he asked Susan and Darla to write a letter to the Olsons, to make sure that they had closure and to express his concern that his quirky sense of humor did not, in any way, upset them.

Moore's close friend Andrew Reeves beat them to it. In a handwritten note (what else?) he began:

"Sheila and Stan Olson: I find this an odd note to write. Several years ago, my friend, Jim Moore, decided that he didn't like just getting bills and ads in the mail. 'It's nice to get real mail sometimes,' he told me, and he figured others felt the same."

In closing, Reeves wrote, "Sadly, the art exhibition has closed. No more postcards from Jim will randomly appear in the mail."

Moore was 38.

In truth, Reeves said, "Jim always worried they'd be freaked out. He didn't want it to come across as stalker-ish."

Rest in peace, Jim. Far from feeling that way, Sheila quickly wrote back to Reeves, expressing her family's true sadness at his untimely passing.

Moore's missives, she said, enriched her family's life, giving them a laugh and a moment to reflect on long-lost friends, or imaginary friends of their own.

She's kept every postcard he sent in a special box.

"My dad," Sheila said, "had a quirky sense of humor, too. If he were alive, he would have tried this himself."

gail.rosenblum@startribune.com • 612-673-7350