She did not go looking for the Red Desert. She came to know it largely by accident, and not even her own accident. In the mid-1990s, a vacationing Boston photographer named Martin Stupich bicycled up Green Mountain on the desert's eastern fringe. On the way down, drunk on altitude, fatigue and wide spaces, he hit a boulder field at full speed, went flying and broke his femur.

After doctors repaired his leg, Stupich convalesced on the couch of a friend who told him stories about the desert: its rainbow-colored badlands and screaming silence; its bands of wild horses; its century-old emigrant trails, scraped tracks still visible through the sage. He left Boston, moved to Wyoming, started carrying his camera into the desert and -- because Wyoming is the kind of thinly populated, conservative state where artists and writers tend to find each other -- made Proulx's acquaintance through a mutual friend. Over lunch one day in 2002, he asked whether she would be willing to write a preface for a book of his desert images.

She thought it would take two weeks, maybe three, to do this favor for her friend -- read some of what had been written about the Red Desert, and cobble together some introductory prose. 

But when she examined the University of Wyoming's library, she found nothing. Further searching through the university's collection of rare books and manuscripts turned up only two records: an 1898 survey of forage plants and a photograph taken 51 years later of a locomotive buried in snow. The largest unfenced region left in the Lower 48 had managed, somehow, to dodge historians and ecologists and nearly every other sort of storyteller. The mystery of it was delicious, and what had begun as a favor became an honest fascination.

The Red Desert has never been a mystery, however, to petroleum geologists, who have long known there is recoverable natural gas here. Now, thanks to a boom fueled by the climbing cost of energy and the Bush administration's permissive policies, the place was changing fast. What was being lost? Nobody really knew. A preface would hardly suffice.

This is the story Proulx tells -- that writing about a third of Red Desert: History of a Place, a new 400-page biography of the region, was a task inspired by curiosity rather than love. That the end result, including Stupich's photographs and contributions from a dozen Wyoming scholars on the desert's history, geology, hydrology, plants, animals and insects, is more an elegy than a plea for conservation.

"My whole life and everything I do," she says, "is motivated by curiosity -- finding out who was here, what they did, what this means, why the snow drifts in the lee of sagebrush in leg-o'-mutton-sleeve shapes, why the skies are the way they are, which animals come to the flowing springs, that sort of thing."

She speaks measuredly, enunciating every syllable. "I find it intensely interesting," she says of the desert: int-er-est-ing. "But, no," she says. "I don't love it."