(Fortune Magazine) -- It's the tail end of the rainy season in the farthest reaches of the South Pacific, and a wind-blown mist falls on the planet's most remote civilization, Rapa Nui, known as Easter Island. Sonia Haoa, a 55-year-old native with olive skin and a long ponytail pulled through a baseball cap, pokes the earth with a walking stick as she considers the scene before her.

Millions of black lava rocks are strewn across a rolling pasture that glistens against an ominous sky. Where untrained eyes would see only randomness in the tableau, the haphazard spew of some ancient volcano, Haoa, like the John Nash character in "A Beautiful Mind," sees intricate patterns. She explains that the size and placement of the rocks vary according to elevation, microclimate, and proximity to the sea. The patterns offer clues about her ancestors' incredible and tragic history: where they lived, what they ate, even their socioeconomic status.

"You have a garden, and a depression, a garden, and a depression," Haoa says, highlighting several groupings of stones. She speaks softly with a heavy Spanish accent. Her kind eyes and gentle tone have earned her a nickname: the Dali Mama.

"In the middle there, there's an Ahu," she adds, using the Rapanui word for the stage built to hold an iconic Moai statue (pronounced mo�-eye). The rocks speak to Haoa about how the ancients narrowly avoided extinction through equal parts desperation and ingenuity. They also remind her of how much work she has left to do.

The island's coordinator of national monuments, Haoa is on a quixotic mission to survey every last piece of archaeology scattered around these 64 square miles of volcanic earth. As her homeland has catapulted from the Stone Age to modernity over the past two decades, attracting ever greater numbers of tourists and straining the fragile infrastructure, she's been quietly cataloging everything from ancient boathouses, the primitive dwellings that her ancestors built on lava foundations, to human remains, scores of buried statues, and man-made "rock gardens."

It may seem like a purely academic exercise, but it's not. Easter Island's economy is inextricably tied to its mysterious past. Tourists come to glimpse the awesome Moai, which stand up to 30 feet tall and weigh as much as 90 tons. The visitors bring money to Rapa Nui - a territory of Chile almost 2,500 miles from the nearest populated landmass - along with pressure to develop grander hotels and restaurants, medical tourism resorts, and even a casino.

But developing here is unimaginably complex. Besides the extreme isolation, copious artifacts lie buried a scratch beneath the surface. As the person with the most complete map of all that archaeology, Haoa has become the gatekeeper through whom developers increasingly must pass.

A huge task

For years Haoa's quest to map her homeland has been a lonely one. Her title may sound impressive, but her work involves trudging along steep slopes in torrential rain and blistering sunshine, back and forth, sketching artifacts with a few young researchers who sleep in tents at the farthest corners of the world for days at a time. Their output has been modest: stacks of paper, line drawings, and spreadsheets - an analog system that hampered Haoa's ability to mark progress.

That is, until two years ago, when she met a man who would change the course of her work forever. Pete Kelsey came to Rapa Nui mainly looking for some R&R. A technical evangelist for the San Rafael, Calif., software company Autodesk (ADSK), he was consulting with customers in Buenos Aires and Santiago in February 2007. With more than $2 billion in annual revenue, Autodesk is a design software firm best known in the world of architecture, but its clients make everything from videogames to running shoes.

Kelsey's division produces AutoCAD Civil3D, civil-engineering software for land, transportation, and environmental development. He travels the world scouting for opportunities and consulting with the likes of Exxon Mobil and federal governments. But this time he brought GPS equipment and a laptop mainly because he thought it'd be cool to survey such a mysterious location.

"I went on holiday, thinking this is a place I need to see before I die," says Kelsey, a gangly music junkie with a baritone that would make a drive-time deejay jealous. "But I also thought there has to be someone here who would benefit from the kind of technology we have. That led me to Sonia."

Before meeting Kelsey, Haoa had been resolved that she'd never finish the survey of the island in her lifetime, that the secrets of her ancestors would die with her, and that developers would plow the sacred gardens. And then Kelsey turned her pencil sketches into digital renderings. He introduced her to the best technology he could find, from laser scanners and GPS receivers to the latest AutoCAD development software. He showed her how to plot the locations of artifacts directly into a computer and add metadata, descriptions, and elevations.

Not only could she easily keep track of which parts of the island had been surveyed, but she could search for, say, rock gardens greater than 50 feet long, and see that they all appeared within 100 yards of the ocean. Haoa had been working in two dimensions. Kelsey gave her a third. "The first time I showed this to Sonia, she burst into tears," Kelsey remembers. "She said, 'You can do that? That would take me six weeks running through pages of paper.'"