A friend of mine had written a book about Native Americans. She used to hangout with them during her youth. She told me about some events that took place a long ago that shaped Native Americans today, about their customs and forgotten traditions and some linguistics, which I used here. The phrase "as long as rivers flow" means for a very long time.You can google Wounded Knee Massacre or Sun Dance to get a glimpse of what it means here, but I tried to reflect from the NA POV, and only went into a first person at the last verse. Kinda "skin-walk" so to speak.