sandytcb49 on Family Tree Circles

My father was born in Corson Co., SD on the Standing Rock Reservation in 1931. His Mother was Echo Sherman Fly. In the book "Taming The Plains" by Rose Tomac Tidball, she interviewed Felix Fly in 1972. My father , Lawrence, was raised for the first seven years by Felix' brother, Sam. I Do not know who my Grandfather was. My Father was adopted in abt 1936 or there abouts by William E. Berry of Illinois. My father, Lawrence ,is in every reservation census up to 1936 as Sams son. I ran across a geneaology on Rootsweb that lists Alma Fly as a daughter of Snow On Her and Tatanka Iyotake (Sitting Bull). I have doubts about this. And am really not looking to relate to Sitting Bull, but I would like to know more of Alma's line and of Thomas Fly( Yuhakinyawpi) I know Thomas was a scout for the government in the 1890's. What else can anyone tell me.? I really am anxious to know if I am part Indian or not? Would my Father be listed as a son of a man not his Father? I know my Father denied that he was Indian but his Mother looks so Indian and he was on the reservation. I would be very happy and proud to be Indian. Thanks