The East Branch Delaware River rises in eastern Delaware County, from a small pond next to a gas station on Route 30 just below the divide with the Hudson River watershed southwest of the hamlet of Grand Gorge and flows initially SSW, through the town of Roxbury. Its upper course winds through a narrow valley containing the river and Route 30. Just past the Middletown town line, the river flows through Wawaka Lake and then receives Dry Brook, whose tributaries drain the town of Halcott, the only part of Greene County in the Delaware's watershed, from the east just outside Arkville. This confluence also puts the Catskill Park Blue Line in the middle of the channel.