Legendary Copper River salmon are prized for their extremely high oil content (which they store in order to swim up the frigid and rugged river). This gives them a richer flavor than other king salmon.
Wild King salmon (aka Chinook or Tyee Salmon) is the largest of the five species of Pacific salmon. King salmon deserves its royal title because of its large flake size, firm, pink-orange flesh, and the highest fat content of all the species, which accounts for its rich flavor.