Delaware • New Jersey • Pennsylvania
New York • United States of America
The Delaware River Basin Commission (DRBC) uses a stream location and identification system based on river mileage. The stream mileage system was published by DRBC staff in 1969 with revisions in 1988. The mileage system for the Delaware River and Bay consists of a "mile zero" and a line along which distances from mile zero are measured (the "mileage line").
What is "Mile Zero?"
Mile zero is located at the mouth of the Delaware Bay (i.e., where the bay meets the Atlantic Ocean) at the intersection of a line between the Cape May Light (New Jersey) and the tip of Cape Henlopen (Delaware) with the centerline of the navigation channel. The position of this point is Latititude 38° 50' 32" N and Longitude 75° 03' 18" W.
Mile 330.7 is the "head" (or beginning) of the main stem Delaware River, where the East Branch of the Delaware meets the West Branch near the town of Hancock, New York.
What is the "Mileage Line?"
From the mouth of the bay to the Bridge Street Bridge in Trenton, New Jersey, the mileage line is the centerline of the main navigational channel.
Between the Bridge Street Bridge in Trenton and Tristate Rock (near the mouth of the Neversink River), river mileages are measured along the New Jersey-Pennsylvania boundary, which generally approximates the centerline of the Delaware River in this reach.
Between Tristate Rock and the head of the main stem Delaware, the river mileages correspond to distances measured along the New York-Pennsylvania boundary.
The stream mileage system information has been updated to include National Oceanic and Atmospheric Administration (NOAA) and United States Geological Survey (USGS) gage locations at various points on the river.