KTC,
The reason I was perplexed by the data is because I know that the local 'natives' are very proud of their heritage and would never misrepresent their ethnicity on something like a census form.
Back when I worked in Michigan our Director of Engineering was from that area. He was half Chippewa (his mother was full-blooded and his father was German American) and his sister was a big wig on the tribal consul. Our university was just a few miles away and after I graduated and was working, I found out where our boss was from so I asked him if he was related to this women whom we were always seeing on the local TV or in the papers whenever there was any controversy down at the reservation and he admitted that YES, that was his 'activist' sister.
When he retired he moved back up there an bought a nice place on the shores of Lake Superior (I stopped into see him and his wife a couple of years ago). I'm not sure if he ever got involved much in tribal affairs since he's living there again as he was gone for nearly 40 years.
He's the only Indian I've ever known who was named 'Swartz'. Looked just like the guy on the Buffalo Nickel.

OCU