The Piercefield Flow Dam is a couple miles downstream from the Setting Pole Dam, which forms Tupper Lake. It is the first in a series of more than two dozen hydroelectric dams and plants on the remaining Raquette River’s drainage, which has more dams or plants than any other river in the Adirondacks. The Raquette River is the second longest Adirondack river, after the Hudson. It flows north for 146 miles from its source, near Blue Mountain Lake, into the St. Lawrence.