In addition to the town and hamlet in New York, two school districts take their name from the river: Wallkill Valley Regional School District, in New Jersey and Wallkill Central in New York (Valley Central also derives its name indirectly from the river).
Mississippi River | River Thames | Amazon River | Columbia River | Hudson River | Colorado River | Potomac River | river | Ohio River | Missouri River | Delaware River | Murray River | River Tyne | Madeira River | Volga River | River Nene | River Clyde | River Trent | River Severn | Amur River | River Wear | Allegheny River | Red River | Dnieper River | Yarra River | Paraná River | River Tees | Fraser River | Yangtze River | Tocantins River |
The road narrows to two lanes as the combined highways begin a slow, gentle descent through less developed areas to the bridge over the Wallkill River, situated at the northern tip of the county's Black Dirt Region.
The borough is in the watershed of the Wallkill River (which flows north, and empties into the Rondout Creek, which flows into the Hudson River near Kingston, New York) and its tributary Glen Brook, which near Sussex forms a small body of water called Clove Lake, part of which is within the borough.
Pochuck Creek, a tributary of the Wallkill River in Sussex County, New Jersey