Landscape ecologists re-create the natural world explorer Henry Hudson encountered when he visited the island of Manhattan 400 years ago.

In his new book, Mannahatta: A Natural History of New York City, Eric Sanderson quotes an archaeologist’s stern warning, “We know nothing about 1609. We can know nothing.” This may seem like a strange cry to include in a project devoted to showing how much can be learned about Manhattan island in 1609, the year Henry Hudson arrived. The archaeologist Sanderson quotes sounds like the Ancient Mariner, leaning out of the book with a glittering eye to stop us on our way to the wedding feast. And yet that warning is exactly right. We can accumulate detail from the past until it’s as deep as the shell-middens that once littered the shores of the Hudson River. We can analyze that detail and calibrate it and layer it until we’re sure we’re dealing with tolerable certainties. And yet we can never know that former world in the way we know our own, with the intuitive knowledge that lives in our bones. Our very existence in 2009 contradicts the existence of 1609. And 1609 contradicts us.

Using a wide array of sources and computerized tools, Sanderson and his research team in the Living Landscape Program at the Bronx Zoo have tried to construct a portrait of Manhattan as Henry Hudson found it. What was the topography like? How diverse were its ecological communities? The humans who lived here—the Lenape—how many were there and how did their presence shape the natural history of the island? To anyone with a feel for the wonder of nature, Sanderson’s answers provoke a powerful nostalgia, a desire to have seen what Hudson saw. The trouble of course is that—had we been there—we could only have seen as Hudson saw. The richness was all in prospect, not in retrospect. The nostalgia we feel for a glimpse of that unspoiled island is an Edenic wish—a desire to have witnessed the original of the world we live in. But it’s also a desire to see— from the vantage of this epically crowded, epically zealous planet—a world in which humans were a minor species.

In many places—most perhaps—the land sustains the past. But in a city like Manhattan—prone to every upheaval except the tectonic—the testimony of the land has been muted. Many of the island’s heights have been leveled. Its hollows have been filled. Its bedrock has been bored and drilled. Its shoreline has been pushed out into the Hudson and the harbor. Its streams and springs and ponds have been vanquished. The history most New Yorkers know is cultural and social history, which preserves, at best, a linguistic link with the old, underlying island and its first European settlers. And even if we’ve given some thought to the natural waterline—to the fact that the city’s West Side Highway, in its lower stretches, would have run well offshore four centuries ago—we haven’t in our minds re-creatured or replanted the island as it once was.

At the heart of Sanderson’s reconstruction is a simple fact— a coincidence, or perhaps not a coincidence at all. A great deal of Manhattan’s ecological topography—and by that I mean the interrelated complex of landforms and life forms—survived into an age of sophisticated cartography. There is a map to the treasure, in other words—the extraordinary British Headquarters Map drawn by British military mapmakers near the end of the Revolutionary War. It shows an aerial view of Manhattan from the Battery to Spuyten Duivel and is as close as we will ever come to flying over the island in 1782. Without the American rebellion, it’s unlikely that a map of this scale and detail would ever have been made. And had cartography—and the surveying practices that make for accurate maps—been less advanced than the technology for settling a New World island, we would never have had this glimpse of the past. The natural world of Manhattan might have faded away, recorded only on primitive maps of the kind that Henry Hudson had used.

Instead, the British Headquarters Map is the foundation for the subsequent over-layering of Sanderson’s data. From above, in 1782, Manhattan is a surprisingly green and knobby place. Only the southern tip of the island—from what is now Canal Street south—has been wholly subjugated, conveniently gridded. North of that, hills rise and creeks cut between them, and where the creeks drain there are salt marshes spreading to the East River and the Hudson. To look at the British Headquarters Map is to realize how hard it is to un-grid the island in our minds, to do away with the illusion of foreshortened skyscrapers and the way the avenues seem to lengthen the city. There is no looking for Broadway here or Central Park to orient ourselves. The most prominent landmarks are Mount Washington—far to the north—and the broad Harlem plains.

And yet even then, there were some 30,000 people on the island, perhaps a hundred times as many as the Lenape who lived there when Hudson first arrived and had long since departed. If you look closely at the British Headquarters Map, you can see small clusters of houses here and there, hugging a creek or an inlet the way they still do in coastal Maine. The relatively poor soils of the island were being tilled and the superb forests cut. Already a way was being made for our modern Manhattan, and that meant the destruction of the natural communities that had been in place for centuries and centuries before. Half of what had been lost already by 1782 were riparian zones.

To reach back, ecologically, 173 years from that military map to the September day when Hudson recorded his landfall takes us beyond the borders of our imagination. You cannot simply graft your experience of some other relatively wild place—the Adirondacks, say—onto the streets of midtown, replacing the one with the other. What has been lost is the particular wildness of Mannahatta—a Lenape word meaning “Island of Many Hills,” whose significance has, appropriately, also been lost. Even Sanderson’s computer-generated illustrations, which show an aerial view of the island as it would have looked in 1609, are unhelpful, except as hints. They show the island at midsummer—unevenly cloaked with trees that have the misfortune of looking somehow generalized.

But every ecological community is rife with particularity, and what would have stunned us is the number of particular communities of flora and fauna on the island, each one as different—far more different, really—as Chinatown is from the Upper East Side. Still more stunning would have been the sense of transition, moving from pitch-pine barrens to oak-hickory forest, from intertidal mudflats to salt marsh to coastal Atlantic cedar swamp. And this perhaps is where we begin to lose our minds—that day in 1609—as we try to take in the dense web of life inherent in each of those landscapes. We have been living with the survivors of those Mannahatta communities—the birds that still frequent Central Park and make it a stopping point in their flyovers, the shad that still run up the Hudson and the eels that run down. But what would it be like to see the fullness of nature instead of the sparseness that remains when we’ve done with it? We have never experienced it, any of us.

Yes, there were wolves in Mannahatta and black bear too. Yes, the rivers would have been thick some times of the year with the runs of anadromous fishes and the skies dark with passenger pigeons. Sanderson and his team have compiled the most accurate census of what would have lived here that has ever been made, and they have tried to give us a feel for the eco-regimes that defined this island—and that this island defined as well. But go back to 1609 and the feel escapes us for the simple reason that we begin, as we think of it, to sound like those first Europeans, overwhelmed by the richness of what they saw. It’s tempting to say that the Manhattan of 2009 would be as incomprehensible to the Lenape as the Mannahatta of 1609 would be to us. But it’s not true. For we live in a human culture essentially at pains to explain itself, to inspire the adaptation of humans. And they lived in a natural world that is largely opaque to us—then and now.

But it’s worth the effort to try to imagine, if only to induce a sense of humility and a sense of recovered wonder. There’s an obvious pride in Manhattan that is missing in Mannahatta, a pride that depends on a very short memory. In principle, time may look like a continuum, but it’s really an infinite number of partings and a wholesale forgetting.


Verlyn Klinkenborg is a member of The New York Times Editorial Board and author of The Rural Life, Making Hay and Timothy.

Originally published in the June 2009 issue of American History. To subscribe, click here