The Mannahatta Project: a model for Portland?

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I’ve been reading Mannahatta: a natural history of New York city (Eric Sanderson, 2009), published on the 400th anniversary of the discovery of Manhattan Island by Henry Hudson.  Using a remarkably detailed British map from 1782-83 as base, Sanderson, a landscape ecologist, went back through time to re-imagine what the island looked like when whites first saw it.  Now a concrete jungle, the 1609 Mannahatta (Lenape for “Island of Many Hills”) was a variegated landscape of hills, forests, meadows, streams and ponds, swamps and beaches; with 55 “ecological neighborhoods” and perhaps 1500 native species.  Sanderson puts back the hills that have been leveled, removes the fill that has erased the ponds and swamps and beaches, and adds the species that have been lost while subtracting those that have been introduced.  He fit the grid of the 1782 map over a contemporary map so one can see where the original ecological communities were.  And most important to me, he pluuged in what history and archaeology have to say about the native Lenape people, mapping their villages, garden plots, trails, and even anthropogenic meadows (Harlem was originally an open plain maintained by fire).  Sanderson is a utopian, and in the last chapter of Mannahatta he looks ahead 400 years to how a New York of the future could make use of natural systems and reincorporate some of the natural places and biological diversity it has lost, into a richer yet sustainable metropolis that combines the best of both natural and urban worlds.

The same could be done for the city of Portland, and I’ll be doing some of that in the last chapters of Before Portland.  We have the pre-and early settlement maps: from the 1841 Wilkes Expedition, showing former shorelines, from the General Land Office survey maps of the 1850’s, showing detailed topography and plant cover at the beginning of settlement, and the 1888 Cleveland Rockwell maps which show the former waterways of the Columbia Slough and other wetlands along the river.  We can add lost and subtract invasive species too.  And most importantly, with the Chinookan village list and list of resource species in Chinookan Peoples, plus information from early history and archaeology, we can come up with a close approximation of how the “people before Portland” lived on the land.  And then maybe, reincorporate the best of those vanished systems into a richer, sustainable Portland of the future.

Mannahatta is a groundbreaking and thought-provoking book.


For a talk by Sanderson on the Mannahatta Project, see

For an image of Portland’s original vegetation cover based on the GLO maps, see the map in John Christy and Ed Alverson’s 2011 “Historical Vegetation of the Willamette Valley, Oregon, circa 1850″ (Northwest Science 85(2): 93-107).