Fonteyn Kill

Fonteyn Kill Fonteynkill, Fountain Kill, Mill Cove Brook
The Fonteyn Kill near its confluence with the Casperkill in June 2007
Etymology	Dutch for Spring Brook
Physical characteristics
Source
• location	Unknown, flows from a culvert beneath Park Avenue
• coordinates	41°41′20″N 73°54′22″W / 41.68898°N 73.90618°W / 41.68898; -73.90618
Mouth
• location	Casperkill
• coordinates	41°40′59″N 73°53′36″W / 41.6830800°N 73.8932900°W / 41.6830800; -73.8932900
Length	1.5 km (0.93 mi)
Basin features
Progression	Casperkill, Hudson River
Waterbodies	Vassar Lake

The Fonteyn Kill (alternatively written Fonteynkill and also known as Fountain Kill and Mill Cove Brook) is a 1.5-kilometer-long (0.93 mi) urban stream (or kill) flowing through Dutchess County, New York, onto the campus of Vassar College, and into the Casperkill. The stream was first on land inhabited by the native Wappinger band before being transferred to the Dutch and then the British. A mill was built along the kill by 1714 and the stream's presence influenced Matthew Vassar's decision to locate his college in the area. The artificial Vassar Lake lies midway down the Fonteyn Kill and was once used for ice skating and boating.

While historically pure, the stream now suffers from urban stream syndrome, partially due to the amount of impervious surfaces within its watershed. Flowing over glacial till, the stream's bed is rich in cobbles and the kill supports populations of benthic macroinvertebrates, trees, shrubs, fish, birds, snapping turtles, and frogs. As of 2016, a Vassar–Cornell University program is monitoring the water quality of the Fonteyn Kill.