Sometimes it's hard to understand the rules of nature, but that's just how it is, whether you like it or not. Baby salmon are born in freshwater, mountainous rivers when their parents are already dead after the extremely gruelling upstream migration from the ocean up into the mountains.
Some salmons can't manage to achieve the final destination and die on the way. Only 4 out of 4,000 manage to reach their birthplace, and every female deposits 4,000 eggs. The young soon return to the ocean, but they are doomed to the same destiny. Their carefree life is unfortunately too short-lasting, and in four years they will face the same deadly challenge.
The best place to observe sockeye salmon are top waterbeds of Adams River, and Fraser River, as well as Shuswap Lake, and the season is approximately between mid-October and late December every year, usually peaking every four years. The last peak of salmon in Canadian rivers was seen in 2018, and the following one is in 2022. During the other years, you might see only hundreds of salmons, not as spectacular.