December 20 marks 199 years since the quiet death of a young woman in a backwater frontier fort. A woman of low status and meager means, her passing would have gone unnoticed if not for one witness who knew about her role in a watershed event: the 1805-06 expedition of Lewis and Clark and the Corps of Discovery. Without her participation, the expedition would likely have failed several times over. Westward expansion, and the history of our nation, might have taken a very different path. This woman was Sacagawea.

Or was she?

When I first set out to write about Sacagawea’s life, I didn’t know more than the basics. I certainly didn’t know about the two very different theories of her death, both of which have passionate supporters. But I was given an assignment: to research and write a comprehensive biography in 6,500 words or less, and I had six months to do it. By the time I was finished, I had become an expert on Sacagawea. Moreover, I had become a passionate fan myself, so that even now, six years after publishing her biography, I can’t get enough of her. But at the beginning, when I faced a daunting task, I started where most anyone would: I Googled her.

Is Google a bad thing? A good thing? Or is it just a thing? Author Philip Pullman, an outspoken advocate of public libraries in Great Britain, says that “using the internet is like looking at a landscape through a keyhole.” True enough. But it’s not the digital-ness that makes it so. It’s the limited-ness. The same can be said for getting all your information from any single source or database, whether that source is Google or one branch of the library. The information is incomplete; it’s filtered, it’s biased.

But it’s a start. Think of it as the first domino.

I like to imagine the research process as a winding, intersecting network of standing dominoes. The dominoes might be books, print journals, digital media, or real people. Just as with the real thing, gathering and setting up the dominoes takes time, planning, and steady guidance. But if it’s done right, one source leads to another, and another, and the result is a beautifully orchestrated tumble. And here’s the real payoff: Students who can set up their dominoes skillfully will have learned not just how to research, but how to research thoroughly enough to formulate their own opinions about what they’ve read. They may even sow a lifelong interest in their topic.

For those reasons, I hope teachers will let kids choose their own research topics to the extent it’s possible. In addition to having a sense of ownership, kids will have more fun studying a topic that already interests them, and goodness knows academics and fun are too rare a combination. Besides, is it possible for anyone to know too much about a topic? Deep digging is where true discovery lies. If a student is dragged kicking and screaming to research and write about Sacagawea, for instance, he may very well stop at the first domino and conclude that the two theories of her death have equal weight. But a student who’s already interested, even casually, will be motivated to dig deeper—deeply enough to sort out truth from speculation, opinion, or misinformation. Best of all, curiosity indulged can grow into a lifelong passion.

While in the throes of my own research, I was thrilled to discover that two theories of Sacagawea’s demise do not simply exist, but persist. And not just online, but in books, too. With that in mind, I wrote the line that became my favorite in the book: “It may never be known for certain which story is true.” How subversive! Suggesting that history is more than a pile of dry, immutable facts. That even experts don’t know everything there is to know. That relying on one or two sources is not sufficient historical research, because who knows what the third source might say, or the thirtieth? That just because something is written down doesn’t necessarily mean it’s The Truth.

Which brings us back to the dominoes. Which dominoes do we choose from the huge pile at our disposal, both in print and online? The challenge is the same as it’s always been: to find reliable information, and to know what to do with it. With the proliferation of information from a mind-boggling array of sources, students need teachers and librarians more than ever. Kids need to learn how to sort through all the information available to them, and how to judge the integrity of that information, so the initial nudge of curiosity can take them down the right paths.

Students who develop strong research skills will come to realize that even reliable sources can conflict. But that’s okay, because kids will learn another valuable lesson: that history is constantly being interpreted, and re-interpreted. They will also learn that their interpretation can be as valid as anyone else’s, especially if they’ve researched thoroughly.

Did Sacagawea die a quiet death in the wilds of the Dakotas in 1812? Or did she live to be nearly 100, among her Shoshone people, spinning yarns of a journey across the continent with a troop of soldiers? “It may never be known for certain...”

What I learned, though, is that she was an extraordinary young woman. She rose above every expectation to hold her own among more than thirty adult white males, and in the process she earned their respect and admiration. She’s earned mine, too.

Building toward that beautifully orchestrated tumble of dominoes—conducting research that begins out of curiosity and progresses to passion and perhaps even to a lifelong interest in a topic—can be a skill that sticks with students through graduation and beyond.

Stacy DeKeyser is the author of the nonfiction books SACAGAWEA and THE WAMPANOAG. Her YA novel JUMP THE CRACKS received a Truman Reader’s Award in Missouri, and has been nominated for South Dakota’s YARP Teen Choice Award. Her newest novel, THE BRIXEN WITCH, will be published in June 2012.