The salmon migrates upward to the mountain against the water flow in order to lay eggs. But the locks here are obstacles for the fish to pass through. So, people installed slides called a fish ladder, through which water and salmons flow from the sea to Puget Sound in spring. The slides flow the water to Puget Sound, carrying the fish. The interesting thing is that because the salmons tend to go against water current by nature, they turn backwards and try to escape the slides the other way around. But, at last, they are moved to the correct direction because the water flow is stronger.
I usually don’t like to give things a too-much spiritual meaning, but found this phenomenon could be a fun metaphor. God prepares a correct way for us. But because of our human knowledge or disposition or human nature, we think our choice is correct, and behave against the flow. However, we cannot help but being carried by the flow, and finally we will find out that the flow was the correct direction.