Complex sentence: Accounts of the Chaska Creature go back many centuries to the Dakota Nation (part of the Sioux nation) referred to the creature as Chiha tanka which roughly translates to Big Elder Brother.
Split into simpler sentences: Accounts of the Chaska Creature go back many centuries to the Dakota Nation (part of the Sioux nation). The Dakota referred to the creature as Chiha tanka which roughly translates to Big Elder Brother.