I have seen the same thing when I used to live in NJ. There was a river that was stocked and I used to fish below a small dam. I frequently saw trout trying to "climb" the dam. May be spawning instinct, but since this was in the spring and the water was warmer than what trout normally like and spawn in I am not sure. I am no expert though. The water was past the temp that trout spawn in and if they were to try to spawn then they "spawn" late in the season. And to the best of my knowledge there were no successful spans by trout in the river.

As for all salmonids trying to swim upstream to spawn, I am not so sure about this. To the best of my knowledge goldens almost exclusively use outlets to lakes to spawn, and cuts and bows also use outlets but also use the inlets as well. I know this really had nothing to do with the original post but I thought I might throw it in anyways.

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Take care everyone and cya around. Mark