The Hudson, at Print Size
Every river, creek and run whose water reaches the Hudson, drawn tall enough to hang in a stairwell. Free, at full resolution, with the words on it or without them.
5,400 × 10,800 pixels at 300 DPI, which is 18 × 36 inches on paper: a portrait, because the watershed is one. It is 135 miles wide and 241 deep and the river runs straight down the middle of it, so the sheet is read top to bottom, the way the water goes.
| Tributary system | Square miles | Miles of stream | Lakes & ponds | Miles to the sea |
|---|---|---|---|---|
| The Hudson itself | 2,697 | 4,205 | 5,937 | 325 |
| The Mohawk | 2,551 | 4,477 | 3,884 | 325 |
| Rondout Creek & the Wallkill | 1,188 | 2,195 | 4,018 | 191 |
| The Sacandaga | 1,055 | 1,580 | 758 | 313 |
| Kinderhook Creek & the Normans Kill | 1,023 | 1,869 | 2,788 | 188 |
| Schoharie Creek | 928 | 1,796 | 2,114 | 295 |
| The Esopus & the Catskill | 838 | 1,679 | 1,737 | 168 |
| The Schroon & the Jessup | 767 | 1,055 | 1,038 | 320 |
| The Hoosic | 714 | 1,342 | 1,010 | 243 |
| The Batten Kill & Fish Creek | 689 | 1,342 | 1,313 | 245 |
| Wappinger, Fishkill & Moodna | 584 | 1,080 | 2,364 | 109 |
| The Croton | 381 | 931 | 1,884 | 87 |
| All of it | 13,414 | 23,550 | 28,845 | 325 |
Half of this river is not a river
The Hudson runs 317 miles from Lake Tear of the Clouds, four thousand feet up on the side of Mount Marcy, to the Battery — walked reach by reach down its own channel, against the 315 it is published at. For the last 153 and a half of those miles it is not a river in any useful sense. It is an arm of the sea: tidal all the way to the Federal Dam at Troy, at sea level the whole way, brackish as far as Newburgh in a dry summer. The sheet paints that stretch in the colour it gives the Atlantic and Long Island Sound, and not in the colour it gives fresh water, because the difference is the most important thing about this river and no map that draws all water the same blue can say it.
Above the dam, 60% of the watershed — 8,103 square miles — drains through that one gate. The other 40% never sees it. Fifty-six named streams reach tidewater on their own, from the Poesten Kill at river mile 151 to the Saw Mill River down at 17 in Yonkers, and the Rondout and the Croton and the Esopus are each as much a mouth of the Hudson as the Hudson is.
An edge that nothing but rain decided
The boundary of this watershed runs 1,268 miles. 1,264 of them are a drainage divide. The watershed reaches five states — New York, Vermont, Massachusetts, Connecticut and New Jersey — and lies on the boundary of none of them: the mile and a half of the outline that touches a state line is two surveys crossing each other, not agreeing. The only stretch of this edge that water did not decide is the two and a half miles drawn across New York Harbour, where the survey had to say somewhere that the river had ended.
That divide was then walked at five-hundred-metre intervals and asked, at every step, what lay on the far side of it. It answers six different seas: 292 miles the St. Lawrence, by Lake Champlain and the Raquette; 278 Long Island Sound, by the Housatonic and the Connecticut; 184 Delaware Bay; 135 Newark Bay, by the Passaic; 119 the Chesapeake, by the Susquehanna; and 59 the harbour itself, straight over the side. Not one mile of it faces Raritan Bay. No other watershed in the northeast is hemmed in by so many.
The city at the mouth owns the top of it
20,143 acres of this watershed's surface is a reservoir belonging to New York City: the Ashokan on the Esopus, the Gilboa dam on the Schoharie, the Rondout at Lackawack, and the whole of the Croton. The water in them does not come down the river. It leaves the basin in a tunnel, runs under the Hudson at Chelsea, and comes back to the estuary at the bottom of Manhattan, a hundred miles below where it fell. It is the largest thing moving water in this watershed and it is not a stream, so nothing else on this sheet can see it.
How far it is to the sea
Every reach was walked down its own river to salt water. The furthest point from the sea in this basin is not on the Hudson and not on the Mohawk proper: it is an unnamed run above Mud Creek at the head of West Canada Creek, in the south-western Adirondacks, 325 river miles above the Battery. That is short as watersheds go — the head of Ischua Creek in New York's Allegheny corner is 2,233 miles from salt water — and it is the point. This is a big basin with a short river down the middle of it.
What it is drawn from
The divide and the twelve tributary systems are the USGS Watershed Boundary Dataset: the sixty-nine HUC10 watersheds that make up the nine Hudson subbasins, unioned. That comes to 13,414 square miles against the 13,400 the watershed is usually published at. The water is the USGS National Hydrography Dataset at high resolution, out of nine subregion files, because a divide is only legible with water drawn on both sides of it. NHD ships an arbolate sum and a stream order for these subregions and both are null in every row, so the network was rebuilt by snapping 352,091 reaches end to end and accumulating length downhill; that number is what sets how wide each stream is drawn. State lines are US Census TIGER.
Printing it
It is a lot of dark ink. A matte or lustre paper holds the fine streams better than glossy, and any shop that takes a 300 DPI JPEG can run it at 18 by 36. Smaller is fine too: at 9 by 18 it is 600 DPI and every headwater is still there.
Free to print and hang, yours or a gift. If you sell it, that is not free. ☕ Coffee if it ends up on your wall.
There are sheets drawn the same way of New York's Allegheny corner, of all five Great Lakes basins, and of the St. Lawrence, which is what lies over the top of this one's northern divide.