East Kill, a 16-mile-long (26 km) tributary of Schoharie Creek, flows across the town of Jewett, New York, United States, from its source on Stoppel Point. Ultimately its waters reach the Hudson River via the Mohawk. Since it drains into the Schoharie upstream of Schoharie Reservoir, it is part of the New York City water supply system. East Kill drains the southern slopes of the Blackhead Mountains, which include Thomas Cole Mountain, Black Dome, and Blackhead Mountain, the fourth-, third-, and fifth-highest peaks in the Catskills, respectively.