On the Canadian side, the road 283 runs along the Canada-US border on 6.4 kilometres (4.0 mi) and crosses the "Northwest Branch Saint John River" at the South East side of the Frontier Lake (Quebec-Maine).
On the US side, a road from Frontier Lake (Quebec-Maine) moves Eastward through the mountains. In addition, a road runs on the North bank on a river segment, downstream of the confluence of the Daaquam River and serves the township T11 R17 WELS in the North Maine Woods.
Geography
The river segment of 1.1 kilometres (0.68 mi) between the bridge of the road 283 and the Canada-US border is considered an extension of Frontier Lake (Quebec-Maine). Consequently, the "Northwest Branch Saint John River" officially rises at the US border and not at the mouth of Frontière Lake in the municipality of Lac-Frontière, Quebec.
This source is located at 6.5 kilometres (4.0 mi) Southeast of Lac Etchemin and 13.5 kilometres (8.4 mi) Northeast of the Canada-US border.
From its source, the "Northwest Branch Saint John River" flows on 20.7 kilometres (12.9 mi) of which 1.1 kilometres (0.68 mi) in Quebec and 19.6 kilometres (12.2 mi) in the Maine:
Higher courses of Northwest Branch Saint John River (segment of 1.1 kilometres (0.68 mi) in Quebec)
1.1 kilometres (0.68 mi) to the South in the municipality of Lac-Frontière, Quebec, to the Canada-US border;
Intermediate Course of the Northwest Branch Saint John River (segment of 9.9 kilometres (6.2 mi) in Maine, up to the confluence of the Daaquam River)
3.9 kilometres (2.4 mi) to the Southeast, up to the limit of the township T12 R17 WELS;
2.5 kilometres (1.6 mi) to the Southeast, up to the confluence of the Daaquam River (from West);
Lower course of the Northwest Branch Saint John River (segment of 9.7 kilometres (6.0 mi) downstream of the confluence of the Daaquam River)
0.6 kilometres (0.37 mi) Eastward up to Bean Creek (from the North);
6.3 kilometres (3.9 mi) to Southeast, up to Oak Brook (from the North);
1.3 kilometres (0.81 mi) Southward forming a curve to the East, up to the boundary between Bellechasse Township and the Township of St. John West, to the limit of Somerset County, Maine;
1.5 kilometres (0.93 mi) to Southeast in the township of T10 R17 WELS Somerset County, Maine, up to the confluence of the river[2]
From the confluence of the Northwest Branch Saint-Jean River, the Saint John River flows Eastward and Northeast through Maine, then East and Southeast through New Brunswick. Finally, the current flows on the North bank of the Bay of Fundy which opens to the Southwest on the Atlantic Ocean.