Penobscot River flows where dam once stood

EAST MACHIAS, ME - OCTOBER 6: A salmon parr swims in a tank at the East Machias Aquatic Research Center in East Machias on Tuesday, October 6, 2015. The hatchery is sited along the East Machias River and cycles the river water through the hatchery in an attempt to imprint the river's characteristics upon the salmon as they are raised at the hatchery. Salmon runs are down in most rivers in Maine and researchers think the reason may be the disappearacne of their food source off Greenland and Atlantic Canada, where Maine's salmon go to feed. (Photo by Gregory Rec/Portland Portland Press Herald via Getty Images)