I visited Bridge 3 today in the park.
I found a pair of dippers and watched a bit of courtship display. The male singing and flying to a rock on which the female stood and she greeted him with a wing flutter. The presumptive male sang a bit then both birds flew upstream to forage.
And that is where things got INTERESTING: I decided to walk up the trail as far as I could to see further upstream as the birds were not in view from the bridge. As I approached I heard some rattle calls and saw a Sharp-shinned Hawk standing on a rock in the stream flow. It stayed for an instant and flew straight up and then upstream. I saw one dipper then two they were frozen in attention; absolutely still. I saw the sharpie further upstream sally out then dive down toward the creek. Perhaps hoping to flush one of the dippers better to nab on the run. Then it came back up and landed on a tree just above the dipper pair. The sharpie waited ,moved laterally in the tree once. Waited for five minutes then flew off. The dippers relaxed and returned to foraging normally.