My daughter, Isabel, was home alone three years ago when a fire raged through hundreds of nearby acres of brush. Our neighbors in Rolling Hills, Calif., were packing up their valuables and getting out.

Isabel, then 15, panicked: What should she pack?

She tried to call but couldn't reach me. Flustered, she ran to my office and grabbed every folder marked "Insurance."

"What's an umbrella policy?" she asked my husband breathlessly, finally reaching him at work.

"Just get out," he said firmly.

A friend picked up Isabel, who carried the insurance folders to safety. Firefighters finally contained the blaze and only a few homes were damaged. As I watched the news coverage the next morning from Washington, D.C., I realized my answer would have been this:

PORTAL TO THE PAST The author eventually scanned her way into various family secrets. Kathleen A. Hughes

Quick, get the 32 boxes of photographs and the 39 photo albums from my bedroom bookcases. Then grab the four cardboard boxes of family papers that are down in storage. Please—very important—take all the framed photographs off the walls.

Also, please grab my mother's 40 books on phonetics and math in the living-room cabinets and my grandmother and great-grandmother's writing on personality type, the Myers-Briggs Type Indicator. Those are on my bedroom bookshelves.

Don't forget the six notebooks with my Wall Street Journal articles from 1980 to 1996, or the box with more recent stories under the old pew.

Only the Beginning

So it was just as well my daughter couldn't reach me. Once home, I began to scan more than 4,000 photographs—one by one—placing each face down on the scanner. It took almost four months of nightly scanning. But when my husband bought a new scanner this year—one with a fast paper feed—a light bulb went on:

I need to completely scan my life.

And for more than a month, that's what I've been doing. Scanning it all, even the college term papers. Obsessively.

"How's the scanning going?" my children ask daily, with mild interest. They did marvel at the Playgirl magazine from 1980 with my one and only published short story. And when I found my mother's letter describing a friend's near-death experience with LSD in the '70s, I read it out loud as a warning.

My family has churned out a lot of paper—but I'm not alone in my digital dilemma. Baby boomers' lives, unlike their children's, are largely recorded on paper. But what's going to happen as all these boxes pass to a digital generation? Will our children treasure or toss them, mystified by the contents?

Therein lies the "paradox of keeping" says David J. Ekerdt, a professor of sociology at the University of Kansas. "The longer you keep something, the more valuable it seems but the less anyone seems to know about its origins."

Taking heed, I am adding descriptions to every scan. "You're not that interested now," I tell my children. "But one day you're going to be very interested. Trust me."

But here's the thing about trying to scan your entire life at age 56: It's hard not to read every letter. And that has been heartbreaking and amusing—not to mention time consuming. In some ways it's therapeutic, and in other ways it's enough to propel me back into therapy. (Scan or shred the old therapy notes? I can't decide.)

So far, I have scanned 2,743 pages, or 16.62 gigabytes. The fragile onionskin paper keeps getting jammed in the scanner. So do the telegrams. But what's really slowing me down is poring over decades of daily details—often recorded in barely legible handwriting.

Buried Treasure

Yet it's the portal to the past that makes the tedium of scanning so worthwhile.

My favorite letters are from college friends in the '70s. Julie, for example, went to visit a friend in France, only to find him living with another woman. "Due to his socialist convictions, Joachim believes that monogamous relations are fascist," she wrote.

Another friend, Jody, wrote from San Francisco: "My biggest problem has been to justify my life. It's hard when your roommate leaves, you're between jobs, you're between lovers, you're between houses and your mother is visiting for Christmas."

Of course, I eventually scanned my way into various family secrets. After my parents met in 1952 at the Philadelphia Art Museum, my father wanted to know all about my mother's first marriage. "I don't want to talk about it," she always responded. And she didn't before dying 20 years later at age 44.

So it was interesting to open a tattered cardboard box and read the letters she wrote to her mother from Middlebury College in the 1940s. "I've met a fascinating new man. His name is John Secord. He's 25, 5'11", rather blond hair, good-looking in a way, very intense eyes."

She details the romance: "He danced cheek to cheek sometimes and much to my surprise that made it hard to breathe or think or speak."

But then come the letters from Reno, Nev., where she went to obtain a divorce. (There's just not enough space to explain what went wrong. But now I know.)

Next up: my father, the '50s and bridge clubs. I discover my early nickname was Prometheus. Cut to 20 years later and new love letters. My mother divorces my father but then writes in despair over the new relationship, shortly before she died.

Some of the letters from this time have been mysteriously removed—leaving only the empty envelopes. "It's like the Nixon tapes," my father says in frustration.

Shared Risk

Perhaps perversely, I decided to send friends and family their scanned letters. This can be dangerous.

Responses varied. A few letter writers were grateful, several were embarrassed, and one was angry. "I just wasn't in the mood to review my old letters," said my friend Julie. "I hate you."

Then there was my father. "I want to read it all!" he said. "Do you have any of your mother's letters from right before the divorce?"

I know better than to send letters back to old boyfriends. That's just rude. I discovered amorous letters from people whose names I don't recognize. Glenn, a photographer whom I apparently met on a train in Greece, wrote:

"It is extraordinary how certain experiences remain permanent fixtures in my memory, to be recalled periodically, for reasons not immediately apparent. I must confess that you are one of those experiences."

No memory of Glenn.

No one seems to have saved my letters. I would love to read them. At least I think I would.

My friend Tom Bain, now a finance professor in Hong Kong, said workmen threw out his letters during a remodel. He had searched the public dump, but to no avail.

And my letters to Jane Goldsmith, a friend I met in the '70s in Paris, also met with disaster. "My garage flooded," she said.

At least my children will have all the family history on one backup drive—assuming I finish this project. I'm now scanning stories I wrote for this paper in 1983. I was writing about orange-juice futures.

It's slow going.

Ms. Hughes is a writer in California. She can be reached at