Copper River kings and Columbia River springers are the same basic animal: early-run chinook with with a high stored fat content. Both are superior eating. The difference is the Copper River kings have been hyped, the springers have not. White kings also are very fatty and great eating. If you catch a Columbia River springer - and the upriver fish are better than those from the lower river tribs -- bleed it immediately and clean it within an hour or two, you'll have the best eating fish on the planet. The earlier in the season you catch them the better, since they do use that fat once they enter freshwater and lose their quality over time.