An amazing, gratifying sight.
Reminds me of a story that Mark Hume wrote about in "The Run of the River". In 1905, one of the first fisheries officers in the Shuswap Region, David Mitchell, camped on the banks of the Salmon River about a mile upstream from the lake. He tied his canoe to stake that was driven into the bed of the stream and went to sleep with not a salmon in sight. In the morning the river was full of sockeye. So many that they were forced up the sloping sides of the river to fall back on those below, and his canoe was resting on the backs of a writhing red mass.
The fish lower downstream, suffocating for oxygen, rushed back to the lack to breathe fresh water through their gills. The rush of fish downstream was like the noise of a thousand ducks rising from a lake. The river became quiet again, flowing by the stake 14 inches below the wet high water mark reached a few minutes before.
Sadly that run of sockeye was extinct 8 years later follwing a series of rockslides caused by railroad construction at Hells Gate.