We were at the dam from about 8:00 AM for 30 minutes. At first, no birds. Then one flew in, sat on the top railing for a couple of minutes, and then flew downstream. After another few minutes a dipper appeared at the top of the (almost) dry cascade, then flew down, entered the nest and did not reappear. Then a few minutes later a dipper flew in to the point in the photo and remained there, apparently on guard duty.PK