The International Appalachian Trail or IAT (fr. Sentier International des Appalaches) is a hiking trail which runs from the northern terminus of the Appalachian Trail at Mount Katahdin, Maine to the northernmost tip of the Appalachian Mountains at Belle Isle, Newfoundland and Labrador.
The IAT was proposed in 1994 to traverse the portions of the Appalachian Mountains which run through Maine, New Brunswick, and Quebec that the Appalachian Trail did not cover. Following route selection, construction of the trail took place through the late 1990s and by 2000, 60-70% was completed.
The Newfoundland extension to the IAT was proposed in 2003 and is still under construction. When complete, the Newfoundland extension will double the existing Maine, New Brunswick and Quebec portion of the IAT with an additional 1,079 km of trail.
The IAT runs northeast from the northern terminus of the Appalachian Trail at Mt. Katahdin, Maine to Mars Hill before following the International Boundary north to Perth Andover, New Brunswick . Upon crossing the border into Canada, the IAT continues up the Tobique River valley before crossing the Miramichi Highlands to the Restigouche River valley and along the Chic-Choc Mountains of the Gaspé Peninsula, ending at the easternmost point in the peninsula - Cap Gaspé in Forillon National Park.
From Cap Gaspé, the IAT skips over the Gulf of St. Lawrence to the island of Newfoundland where the trail picks up again at Channel-Port aux Basques and follows the west coast of the island up the Great Northern Peninsula before terminating at the island's northernmost tip - Cape Bauld. From there the IAT skips over the Strait of Belle Isle to the actual northern terminus of the Appalachian chain at Belle Isle.
Scenic highlights along the route include:
- Mars Hill Mountain (Maine)
- Saint John River valley (New Brunswick)
- Tobique River valley (New Brunswick)
- Mt. Carleton (New Brunswick) - highest elevation in the province
- Matapedia River valley (New Brunswick and Quebec)
- Mt. Logan and Mt. Jacques Cartier (Quebec)
- Codroy River valley (Newfoundland)
- Anguille Mountains (Newfoundland)
- Lewis Hills (Newfoundland) - highest elevation on the island
- Humber River valley (Newfoundland)
- Long Range Mountains (Newfoundland)