I was back at the Dam this morning and again this evening. I saw a muskrat in the pond behind the visitors center then I met a fellow birder   We went looking   for the Long tailed duck. We went all the way north past the ravine and no sign of it was found. We did see two hooded mergansers, some redheads, a  bufflehead and some scaup and some goldeneye.. No sign of the Osprey yet though I expect them any day. We saw a couple of wood ducks in the river  and another one in the pond between the trails on the north side. South of the dam about half a mile or so we saw at least 15 great blue herons on nests in the rookery and a red tailed hawk near a herons nest. A friend that we ran into said that he had seen two red tails on a heron nest for the last two or three days which has happened there before.  Tonight I counted 18 great blue herons at the rookery but did not see the red tailed hawk. It was a beautiful night.  The link shows a couple of photos.
Ron Taube Coon Rapids