The Lake, End to End

Greenwood Lake is a ribbon of water about seven miles long by the state’s count and barely two-thirds of a mile across at its widest, running north from Hewitt in New Jersey up into Orange County, New York. Roughly half the surface lies in each state. Steep wooded ridges hem it in on both sides, which is why the shoreline looks the way it does and why the wind does what it does.

Sources disagree on the length — NYSDEC and Wikipedia say seven miles, the New Jersey commission and most maps say nine, a West Milford surveyor measured 7.6. We use the lower, state-agency figure throughout this site. The surface is around 1,918 acres either way.

Two lakes, joined in the middle

This is the thing worth understanding before you push a boat out. The northern basin, in New York, is the original lake: up to fifty-seven feet deep, steep-sided, cold and clear. The southern basin — our end — is essentially man-made, and it is about ten feet deep at its very deepest.

In 1836 the Morris Canal & Banking Company dammed the outlet to feed the canal, raising the water about twelve feet. That flooded the farmland at the southern end, backed the lake up into Belcher Creek, and cut Chapel Island off from the shore. The trees that were standing on that farmland are still standing on the bottom, which is why there are stump fields south of Storms Island and why the shallow end grows weed the way it does.

It was not the first dam. Peter Hasenclever had already dammed it around 1765 to drive the forges at the Long Pond Ironworks downstream — the ruins of which you can walk through in twenty minutes from here. New Jersey took ownership of the lake in 1924 when the canal system was dismantled, and still operates the dam. The Wanaque River is the only outlet, and it feeds reservoirs that supply drinking water to more than three million people.

The Long Pond Ironworks museum · How the house treats the water

What each stretch is like

Four reaches, and the boundaries are not arbitrary: each one is a thing you can see from a boat. Fox Island, Storms Island, and the state line — which crosses within a few hundred yards of Storms, so the two are effectively one landmark. The distances below are measured along the lake’s axis from the southern tip, which is a straight line through a bent lake: a boat threading the coves does more, and the figure the state publishes for the whole lake is longer still.

Where to put a boat in

If you have brought your own, the dock here is the easy answer. For everything else, the south end of this lake has never had a proper free public ramp, which surprises people.

The three islands, and why you cannot land on any of them

Fox Island sits near our end in the shallow basin, about an acre, wooded, and marks where Hasenclever’s original dam stood. Storms Island is the landmark that roughly divides the shallow south from the deeper north. Chapel Island, on the New York side, is the one with the story: it held a small chapel reachable only by boat, which burned around 1948.

All three are private and residential today, with houses on them. There is no public island to picnic on, whatever you may have been told — picnicking here is shore-based, at Brown’s Point on our side or Morahan Park at the north end.

Reading the water

The single thing that will decide whether your paddle is lovely or grim is wind. The lake runs north–south and so does the weather, which means a breeze has miles of open water to build on before it reaches you. The wide middle and the New York basin get rough fastest.

Go at first light. The water is glass, the eagles are fishing, and the motorboats are not up. Traffic builds through the late morning on a summer weekend and the central lake turns into a wake-filled highway; the afternoon usually brings wind on the axis. If sustained wind is running north or south above about twelve to fifteen miles an hour, stay in the southern coves and Belcher Creek and have a good morning anyway.

The rules, including the one everybody gets wrong

• New Jersey waters: 45 mph maximum by day, 15 mph from half an hour after sunset to half an hour before sunrise, and 5 mph within 200 feet of any shore, dock, raft or moored boat.
• There is no daytime 15 mph zone at the south end. It is a common local belief and it is wrong — the 15 is the after-dark limit and it applies to the whole New Jersey portion.
• New York waters run under state navigation law and the village’s own ordinance, including no wake north of the buoys at the two arm entrances, and no personal watercraft between sunset and sunrise.
• A Coast Guard-approved life vest for every person aboard, both states. In New Jersey children twelve and under must be wearing one while under way.
• Given how much traffic this lake carries, treat it as a wear-it lake rather than a carry-it lake, whatever your age.

What can actually go wrong

Boat wake is the real hazard, not the water. Stay near a shore, be conspicuous, and cross open stretches early. After that it is the stumps: the flooded farmland south of Storms Island is still down there and can catch a paddle, a fin or an ankle, and it is worse in the autumns when the state draws the lake down.

That drawdown happens roughly every four or five years for weed control and dock repair, starting around the second Tuesday of October and refilling from January. In a drawdown autumn expect mudflat, stump and a good deal less water than the map suggests.

Algal blooms, honestly

Greenwood Lake has a recurring problem with cyanobacteria, and it is worst at the New Jersey end, because our end is shallow, warm and productive. In July 2019 the state advised the public to avoid contact with the water in the New Jersey portion altogether. Advisories returned in 2023, restricting swimming, kayaking, wading and eating the fish.

It is not every year and it is not all summer — it is a warm, calm, late-season phenomenon, roughly July to September. But if you are here in August, look at the water before you get in it, keep children and dogs away from any green or blue-green scum, and check the state’s current advisory. We will tell you if there is one when you arrive, and it is part of why the house does not treat its lawn.

Why the house is run the way it is · What lives in it · Guidelines for your stay

Three mornings, from our dock

The old lake

For about fifty years from the 1870s this was a Gilded Age resort reached by rail from Montclair. Steamboats carried guests up from the southern depot to fifteen-odd hotels — the largest of them a four-hundred-passenger steamer called the Montclair, which docked where the town beach is now. Babe Ruth drank here. Jasper Cropsey painted the lake from 1843 onward. In winter they cut the ice and shipped it south.

Almost none of the hotels survive. What survives is the shape of the shoreline they built on, and the reason the lake has so many houses on so little frontage.

The Munsee called it Quampium. The settlers called it Long Pond, for the obvious reason, and the ironworks downstream still carries that name. Greenwood Lake came later, with the hotels.

SourcesNYSDEC · Greenwood Lake Commission