Even for a writer known for pulping juice out of seemingly desiccated subject matter, publishing a 660-page door jam on geology seemed a bit extreme. There is always with McPhee a gnawing sense that perhaps he is choosing his subjects precisely for their apparent dullness, tossing down the gauntlet, as it were, before contemporary sensibilities of what makes for good stories. In a time when so many nonfiction writers work with one eye trained on Hollywood, hoping to follow their narrative arcs and high concepts into the sunlit uplands of first dollar gross, McPhee’s work remains resolutely uncinematic.

That is certainly the case for Annals, whose frequent declivities, buried geosynclines, and discordant batholiths make it too-rugged terrain for Hollywood to file a claim on. Which is not the same thing as saying the subject is bland. Indeed, as McPhee notes early on in the book, geology is known as a descriptive science. And so it is. In making the road cuts yield up their secrets, McPhee finds keys to time machines parked at regular intervals by the side of the highway. Consider McPhee’s examination of a canyon wall in Nevada that holds sand and pebbles from the ancient shoreline of the Meramecian straits off the then-coast of North America:

The strait was warm and equatorial. The equator ran through the present site of San Diego, up through Colorado and Nebraska, and on through the site of Lake Superior. The lake would not be dug for nearly three hundred and forty million years. If in the Meramecian you were to have followed the present route of Interstate 80 moving east, you would have raised the coast of North America near the Wyoming border, and landed on a red beach. Gradually you would have ascended through equatorial fern forests, in red soil, to a high point somewhere near Laramie, to begin there a long general downgrade among low hills to Grand Island, Nebraska, where you would have come to an arm of the sea. The far shore was four hundred miles to the east, where the Mississippi River is now, and beyond it was a low, wet, humid, flat terrain, dense with ferns and fern trees–Illinois, Indiana, Ohio. Halfway across Ohio, you would have come to a second epicratonic sea, its far shore in central Pennsylvania. In New Jersey you would have begun to ascend mountains and ever higher mountains, their summits girt with ice and capped with snow, not unlike Mt. Kenya…. Reaching the site of the George Washington Bridge, you would have been at a considerable altitude, looking at mountains and more mountains before you in future Africa.

I’m tempted to say that passages like this one and many others in Annals of the Former World have had a lingering effect on me, but that does not quite describe the impact of the book. Many books haunt, but while I may have pondered the cruel fate of Tolstoy’s Madame Karenina, or felt the visceral despair of Saint Augustine, even after returning their stories to the shelf, no work has altered my perception of the world and our place in it more than McPhee’s geology tome. It caused a shift in conscience, an alteration in the currents of my thought that, even now, carve out fresh new channels for my perceptions to tumble down. Usually those kinds of seismic events are produced between the covers of religious or philosophical tracts or, perhaps, by a great novel. But geology? Over the years I’ve often attempted to explain the book’s tug on my psyche, but usually only receive looks of bemused indulgence. Such reactions have often made me wonder if Annals, like Finnegan’s Wake, is one of those books that many have on the shelf but few have actually read. I raised the question with David Remnick, McPhee’s editor at The New Yorker, of whether the book, despite having won a Pulitzer Prize, is sometimes overlooked by readers. ”I think it really is an underrated masterpiece,”said Remnick, a former student of McPhee’s at Princeton. ”It got made fun of a little bit as ‘that story about rocks.’ ”

Douglas McCollam is a contributing editor to CJR.