What is a steelhead?

   Steelhead, or hardhead, is a common name applied to a large game trout, Salmo gairdneri, found in the sea and in fresh-water streams along the Pacific coast of North America from California to Alaska. The steelhead trout, which attains a length of about thirty inches, is believed by many ichthyologists to be identical with the rainbow trout, which has long been considered a separate species, Salmo irideus.