| Wallkill River | |
|---|---|
Islands in the river near Walden, NY | |
The combined watersheds of the Wallkill andRondout Creek | |
| Native name | Twischsawkin |
| Location | |
| Country | United States |
| State | New York,New Jersey |
| Counties | Ulster, NY,Orange, NY,Sussex, NJ |
| Cities | New Paltz, NY,Walden, NY,Montgomery, NY,Sparta, NJ |
| Physical characteristics | |
| Source | Lake Mohawk, New Jersey |
| • location | Sparta,Sussex County,NJ |
| • coordinates | 41°01′58″N74°38′38″W / 41.03278°N 74.64389°W /41.03278; -74.64389 |
| • elevation | 720 ft (220 m) |
| Mouth | Rondout Creek |
• location | Rifton,Ulster County,NY |
• coordinates | 41°51′13″N74°02′55″W / 41.85361°N 74.04861°W /41.85361; -74.04861 |
• elevation | 0 ft (0 m) |
| Length | 88 mi (142 km)[1] |
| Basin size | 785 sq mi (2,030 km2)[2] |
| Discharge | |
| • location | Gardiner, NY[3] |
| • average | 1,365 cu ft/s (38.7 m3/s) |
| Basin features | |
| Tributaries | |
| • left | Shawangunk Kill |
| • right | Papakating Creek |
TheWallkill River, atributary of theHudson, drainsLake Mohawk inSparta,New Jersey, flowing from there generally northeasterly 88.3 miles (142.1 km)[1] toRondout Creek inNew York, just downstream ofSturgeon Pool, nearRosendale, with the combined flows reaching the Hudson atKingston.
The river is unusual because it flows north between two major south-flowing rivers, theHudson and theDelaware River. It also has the unusual distinction of being a river that drains into acreek, due to beingimpounded shortly before the Rondoutconfluence into a small body of water calledSturgeon Pool nearRifton, and what reaches the Rondout from there is the lesser flow.


The broad valley of the Wallkill River nestles between the mainAppalachian Mountains and theNew York-New Jersey Highlands, supporting much localagriculture. It is a part of theGreat Appalachian Valley. In the beginning of its course it drains the eastern section ofSussex County, New Jersey, then flows through theWallkill River National Wildlife Refuge at the New Jersey/New York state line. Most of the New Jersey portion is navigable by canoe. Then it is heavily diverted as it flows through the richBlack Dirt Region ofWarwick. Until drainage projects were built here, this region was known as theDrowned Lands. After lending its name to the town ofWallkill, in northernOrange County, it begins to regain its volume as it passes byOrange County Airport,Montgomery and throughWalden, wheredams have been built in the past to provide power for localindustry. The largest, in Walden, still is used byNew York State Electric and Gas today.
After briefly serving as the line between Orange andUlster counties, it passes byWallkill, the second community to take its name from the river, and then the striking scenery of theShawangunk Ridge is visible as it winds past theUlster County Fairgrounds andNew Paltz, where itsfloodplain becomes more noticeable, on the way to its mouth at the Rondout.
The Wallkill tends to cross political borders much more often than it forms them, at least in New York (in New Jersey it divides several townships). Other than the brief segment that follows the Orange-Ulster line, there is only southern Orange County, where it divides the towns ofMinisink,Wawayanda andWallkill on its west fromWarwick andGoshen to the east. Two villages, Montgomery and New Paltz, are also bounded by the river in part.
In addition to thetown andhamlet in New York, two school districts take their name from the river:Wallkill Valley Regional School District, in New Jersey andWallkill Central in New York (Valley Central also derives its name indirectly from the river).




Native Americans knew the river asTwischsawkin. At least three prehistoric rock shelters have been found inarchaeological digs in the region. For the indigenous peoples, it was not only important for itsarable land but for itsgeological resources. The river and its valley are abundant inflint andchert, from which they madespear points andarrowheads.[4]
Europeansettlers of the region named it first the Palse River, after New Paltz. Later, when it was clear that the river continued well beyond the original New Paltz patent, it took after theWaal river in their nativeNetherlands. They worked their way down it from the Hudson Valley in the 17th century, and were followed by the British after the colony changed hands.[4]
Settlers recognized the agricultural possibilities of the Drowned Lands almost as soon as they moved in. Efforts to divert the river and create more farmland appear to have begun as early as 1760. It would take 66 years, however, before acanal succeeded in draining the land and making enough available to profitably cultivate.[4]
By that time industry was beginning to harness the river, too, as Jacob Walden established hismill in the village downriver that would later take his name. Millers in the Black Dirt Region clashed heavily with farmers in what were known as the Muskrat and Beaver Wars for decades afterwards, since the millers needed the water to flow freely while the farmers depended on keeping it diverted. In 1871 the farmers finally won. What industry there was would be confined to Montgomery and Walden where therailroad ran nearby.[4]
In Ulster, vacationers frequented the Springtown neighborhood of New Paltz during the late 19th to early 20th century, making use of the Wallkill for recreation. Many of the larger older homes still on Springtown Road were boarding houses for these people escaping from the summer heat to the cool banks of the Wallkill River.
In August 1955, the river experienced record-breaking flooding when hurricanesConnie andDiane brought heavy rainfall to the region.[5] Heavy flooding of the river and its smaller tributaries from theApril 2007 nor'easter forced a number of road closures and evacuations of homes in itsflood plain in central Orange County.

There have been several efforts in the late 20th and early 21st centuries to clean up the river.
At the turn of the century, a Wallkill River Task Force was formed, with representatives from both Ulster and Orange counties. From the 'Acknowledgements' of the "Wallkill River Watershed Conservation and Management Plan":
"A crucial development in the history of Wallkill Watershed protection efforts was the scheduling of a Wallkill River conference in 1998. Held at Orange County Community College and organized by the Orange County Land Trust (OCLT), this conference could be considered the birth of the Wallkill River Task Force (WRTF) – a ‘project’ of the OCLT. While some focus on this Watershed was already occurring amongst government agencies, the WRTF created a non-governmental group that actively sought the volunteer participation of farmers, business people and other ‘ordinary’ citizens, in addition to government and conservation agency employees, to provide for broad-based leadership in protecting the Wallkill River and its watershed lands."
One result of that Task Force's work was the drafting of a conservation and management plan.[6]Riverkeeper's water-quality program[7] has been testing samples at many places along the river with the help of citizen-scientists.[8]
In late summer 2016, the Wallkill River Watershed Alliance, along with Riverkeeper, documented a potentially toxic large blue-green algae bloom, prompting the two groups to warn that could be harmful to people, dogs or other pets.[9] After the samples were taken from the River, New York'sDepartment of Environmental Conservation confirmed a Harmful Algae bloom with High Levels of Toxins.[10][11] Riverkeeper responded by calling on government officials to define the causes of the algae.[12]
The Wallkill has 69 tributaries in New York alone. Thirty are named.[2]
Moving downriver (south to north)