Editing Delaware River (section)

==Course==
{{Redirect|Delaware River Valley|the metropolitan area along the Central and Lower Delaware|Delaware Valley}}

===West Branch of the Delaware===
{{main|West Branch Delaware River}}

The [[West Branch Delaware River|West Branch of the Delaware River]], also called the Mohawk Branch, spans approximately {{convert|90|mi|km}} from the northern [[Catskill Mountains]] to its [[confluence]] with the Delaware River's East Branch at [[Hancock, New York]]. The last {{convert|6|mi|km}} forms part of [[New York–Pennsylvania border|the boundary between New York and Pennsylvania]].

The West Branch rises in [[Schoharie County, New York|Schoharie County]], New York at {{convert|1886|ft}} above sea level, near [[Mount Jefferson (New York)|Mount Jefferson]], and flows tortuously through the plateau in a deep trough. The branch flows generally southwest, entering [[Delaware County, New York|Delaware County]] and flowing through the towns of [[Stamford, New York|Stamford]] and [[Delhi, New York|Delhi]]. In southwestern Delaware County it flows in an increasingly winding course through the mountains, generally southwest. At [[Stilesville, New York|Stilesville]] the West Branch was impounded in the 1960s to form the [[Cannonsville Reservoir]], the westernmost of the reservoirs in the New York City water system. It is the most recently constructed New York City reservoir and began serving the city in 1964. Draining a large watershed of {{convert|455|sqmi}}, the reservoir's capacity is {{convert|95.7|e9USgal|m3}}. This water flows over halfway through the reservoir to enter the {{convert|44|mi|km|adj=on}} West Delaware Tunnel in [[Tompkins, New York|Tompkins]], New York. Then it flows through the aqueduct into the [[Rondout Reservoir]], where the water enters the {{convert|85|mi|km}} [[Delaware Aqueduct]], that contributes to roughly 50% of the city's drinking water supply. At [[Deposit (town), New York|Deposit]], on the border between [[Broome County, New York|Broome]] and Delaware counties, it turns sharply to the southeast and is paralleled by [[New York State Route&nbsp;17]]. It joins the East Branch at {{convert|880|ft}} above sea level at [[Hancock (town), New York|Hancock]] to form the Delaware.

===East Branch of the Delaware===
{{main|East Branch Delaware River}}

Similarly, the [[East Branch Delaware River|East Branch]] begins from a small pond south of [[Grand Gorge, New York|Grand Gorge]] in the [[List of towns in New York (state)|town]] of [[Roxbury, New York|Roxbury]] in [[Delaware County, New York|Delaware County]], flowing southwest toward its impoundment by New York City to create the [[Pepacton Reservoir]], the largest reservoir in the [[New York City water supply system]]. Its tributaries are the Beaver Kill River and the Willowemoc Creek which enter into the river {{convert|10|mi|km|spell=in}} before the West Branch meets the East Branch. The confluence of the two branches is just south of [[Hancock (village), New York|Hancock]].

The East Branch and West Branch of the Delaware River parallel each other, both flowing in a southwesterly direction.

===Upper Delaware Valley===
{{see also|Upper Delaware Scenic and Recreational River}}

From [[Hancock, New York]], the Delaware flows between the northern [[Pocono Mountains|Poconos]] in Pennsylvania, and the lowered shale beds north of the Catskills. The river flows down a broad [[Appalachian Mountains|Appalachian]] valley, passing [[Hawk's Nest (Orange County, New York)|Hawk's Nest overlook]] on the Upper Delaware Scenic Byway. The river flows southeast for 78 miles through rural regions along the New York-Pennsylvania border to Port Jervis and  [[Shawangunk Ridge]].<!--{{rp|p.9}}
* Mongaup River
* Neversink River-->

===The Minisink===
{{Main|Minisink}}

At [[Port Jervis, New York|Port Jervis]], New York, it enters the Port Jervis trough. At this point, the Walpack Ridge deflects the Delaware into the Minisink Valley, where it follows the southwest [[Strike and dip|strike]] of the eroded [[Marcellus Formation]] [[bed (geology)|beds]] along the Pennsylvania–New Jersey state line for {{convert|25|mi|km}} to the end of the ridge at Walpack Bend in the [[Delaware Water Gap National Recreation Area]].<ref name="White">{{cite web|url=http://www.njgeology.org/enviroed/newsletter/v2n1.pdf |title=Karst in the Delaware Water Gap National Recreation Area |author1=White, Ron W. |author2=Monteverde, Donald H. |work=Unearthing New Jersey Vol. 2, No. 1 |date=Feb 2006 |access-date=June 7, 2008 |publisher=New Jersey Geological Survey |archive-url=https://web.archive.org/web/20080910033019/http://www.njgeology.org/enviroed/newsletter/v2n1.pdf |archive-date=September 10, 2008 |url-status=live}}</ref><ref name="White1882">{{cite book| author = White, I.C. |author2=Chance, H.M. | year = 1882 | title = The geology of Pike and Monroe counties | series = Second Geol. Surv. of Penna. | location = Harrisburg | volume = Rept. of Progress, G6 | pages = 17, 73–80, 114–115}}</ref>
The Minisink is a [[buried valley]] where the Delaware flows in a bed of [[glacier|glacial]] [[till]] that buried the eroded bedrock during the [[last glacial period]]. It then skirts the [[Kittatinny Mountains|Kittatinny ridge]], which it crosses at the [[Delaware Water Gap]], between nearly vertical walls of [[sandstone]], [[quartzite]], and [[conglomerate (geology)|conglomerate]], and then passes through a quiet and charming country of farm and forest, diversified with plateaus and escarpments, until it crosses the Appalachian plain and enters the hills again at [[Easton, Pennsylvania|Easton]], Pennsylvania. From this point it is flanked at intervals by fine hills, and in places by cliffs, of which the finest are the Nockamixon Cliffs, {{convert|3|mi|0}} long and above {{convert|200|ft}} high.

The [[Appalachian Trail]], which traverses the ridge of Kittatinny Mountain in New Jersey, and Blue Mountain in Pennsylvania, crosses the Delaware River at the Delaware Water Gap near Columbia, New Jersey.

===Central Delaware Valley===
{{Multiple image
| width=200
| image1 = Aerial view of Trenton bridges, December 2022.jpg
| image2 = 2023-09-04 13 06 32 View of the Falls of the Delaware at low tide, looking west from Trenton, Mercer County, New Jersey towards Morrisville, Bucks County, Pennsylvania.jpg
| footer = The Falls of the Delaware at [[Trenton, New Jersey|Trenton]], where the river becomes tidal. Left - aerial view looking northwest; right - ground view from the New Jersey banks
}}
In [[Easton, Pennsylvania]], the [[Lehigh River]] joins the Delaware. At [[Trenton, New Jersey|Trenton]], the Delaware crosses the [[Atlantic Seaboard Fall Line]] with a drop of {{convert|8|ft}}.

===Lower Delaware and Tidewater===
{{See also|Delaware Valley}}

Below [[Trenton, New Jersey|Trenton]], the Delaware flows between [[Philadelphia]] and [[New Jersey]] before becoming a broad, sluggish inlet of the sea, with many marshes along its side, widening steadily into its great estuary, [[Delaware Bay]].

The Delaware River constitutes the boundary between Delaware and New Jersey. The Delaware–New Jersey border is actually at the easternmost river shoreline within the [[Twelve-Mile Circle|Twelve-Mile Circle of New Castle]], rather than at mid-river, mid-channel or [[thalweg]], so small portions of land lying west of the shoreline, but on the New Jersey side of the river, are [[pene-exclave]]s under the jurisdiction of Delaware. The rest of the borders follow a mid-channel approach.