The valley of the river Pherrins is a convenient passage for connecting the Island Pond to the Norton Pond which is the head of water of the Coaticook River flowing to the northeast across the border of Quebec and Vermont.
From its source, the river Pherrins flows on 16.9 kilometres (10.5 mi) according to the following segments:
1.9 kilometres (1.2 mi) toward the Northwest racing down the cliff on 324 metres (1,063 ft) down to the railway crossing the valley of Pherrins River and the Coaticook River;
2.5 kilometres (1.6 mi) toward the Southwest, crossing two small lakes up to the confluence of a stream (from the North);
0.5 kilometres (0.31 mi) toward Southwest, up to the limit of Orleans County;
1.2 kilometres (0.75 mi) toward the Southwest, collecting the waters of a mountain stream (from the Northwest) up to the Pine Brook (from the East);
2.1 kilometres (1.3 mi) to the South up to the discharge of Underpass Pond (from the East);
2.8 kilometres (1.7 mi) to the South up to the limit of Essex County;
5.9 kilometres (3.7 mi) to the Southeast up to its confluence[1]
The Pherrins River empties on the Northwest shore of the Clyde River at 0.9 kilometres (0.56 mi) downstream from the mouth of the Island Pond in the area of Brighton, Vermont. This confluence is located on the west side of Island Pond.