The river flows in a northeasterly direction from its source in the Appalachian Mountains of northwestern New Brunswick to Chaleur Bay. Its meander length is approximately 200 kilometres. The Restigouche is fed by several tributaries flowing south from Quebec's Notre Dame Mountains on the western edge of the Gaspé Peninsula (Kedgwick River, Gounamitz River, Patapédia River and Matapédia River) as well as the Upsalquitch River flowing north from New Brunswick's Chaleur Uplands.
Located mostly in New Brunswick, the river forms the inter-provincial boundary between the two provinces from its confluence with the Patapédia River to its mouth at Dalhousie, New Brunswick and Miguasha, Quebec where it discharges into Chaleur Bay.
The estuary is 25 km long and extends from its mouth at Dalhousie to Tidehead, New Brunswick and is an important stopover for sea ducks, especially Black Scoters and Sea Scoters, during migration. This estuary has been designated an Important Bird Area by the Canadian Wildlife Service.
The HMCS Restigouche, a World War II Canadian naval destroyer, was named after this river.
Home to the Mi'kmaq Nation for centuries, the Restigouche watershed is a land of many mountains and unspoiled vistas, as well as significant timber resources. French settlers established several communities on its banks during the 17th and 18th centuries but the area remained largely void of European settlement until the decades following the French and Indian War. The Battle of Restigouche was a naval action between British and French forces which was fought on the river in 1760 during the latter stages of the war. Those French vessels were to supply Quebec with supplies and ammunition following the loss of the battle of the Plains of Abraham, but since the ships never made it, the city never had a chance to be retaken.
The establishment of the colony of New Brunswick for United Empire Loyalists refugees following the American Revolutionary War saw modest influx of several families to the area but the most significant impact came from Scottish settlers following the Highland Clearances. Many Scottish families found work in the infancy of the timber industry and were at the forefront of industrialization of the forests throughout the 19th and early 20th centuries. The Restigouche River and its tributaries became a highway for log drives, bringing timber to the dozens of sawmills at Campbellton and Dalhousie. Further industrialization saw pulp and paper mills established in those communities by the 1930s to take advantage of the Restigouche watershed's timber resources.
 Salmon fishing
The river is world-renowned for its Atlantic Salmon fishing. Fly fishing/angling has become a significant source of revenue for many outfitters in the region and a 55 kilometre stretch of the Restigouche has been designated part of the Canadian Heritage Rivers System as a result.
For more than 100 years, the world's wealthiest people have come to enjoy the river's tranquil beauty and perfect canoeing conditions to fish for salmon. Among the VIPs who have been guests at the river's fishing lodges include the Duke of Windsor and Wallis Simpson, Hubert Humphrey, Ted Williams, Lord Beaverbrook, Bing Crosby, Louis St. Laurent, Maurice Richard, Norman Schwarzkopf, George H. W. Bush, and Brian Mulroney, to name but a few.
Part of the draw for salmon fishing on rivers in New Brunswick and Quebec is its exclusivity - the provincial government's Department of Natural Resources auctions fishing leases for physical sections of the river and riverbed to the highest bidder. Many private fishing lodges have been established on the Restigouche which are owned and operated by major corporations and the wealthy. Such leases are time-limited and, for the best fishing pools, can reportedly run into the millions of dollars for fishing rights lasting for only a few years. Leaseholders must obey all provincial conservation laws by hiring their own fish wardens to patrol each leased section of the river and all persons sanctioned by a particular leaseholder to fish in a lease must hold a provincial angling license. The general public are permitted a right of navigation on the river, as per Canada's Navigable Waters Protection Act, however they are not permitted to drop anchor in, or cause any disturbance to the river bottom, and absolutely not permitted to fish in a particular lease area.
New Brunswick's wealthy Irving family has owned a lodge for many years at one of the best fishing holes on the river - the confluence of the Kedgwick with the Restigouche - and the Government of New Brunswick also maintains a "rustic" lodge in nearby Larry's Gulch which has operated as an exclusive resort/get away for politicians and friends of the government in office. William Kissam Vanderbilt enjoyed fishing on the river so much that he had a private fishing lodge built, hiring the famous New York City architect Stanford White to design and oversee construction of the property called Kedgwick Lodge and fuelling the love affair of corporate America with the Restigouche.
The Canadian business elite outside of the Maritimes haven't been nearly as enamoured with the river as Americans, although several prominent Toronto families including the Eatons did have a presence. This is largely due to geography where Boston, New York and Philadelphia were relatively close helping make the region a small summer colony.
 See also
- http://www.elements.nb.ca/Theme/estuaries/mike/lushington.htm Éléments, Online environmental magazine