This does not surprise me. The oldest human remains yet found in the Americas (Kennewick Man, Spirit Cave Mummy, etc) are all non-Amerind in their anthropological characteristics. There were also persistent legends among the Great Lakes tribes about occasional blue eyed offspring, which possibly coincides with the whole "Minnesota Vikings" legend (i.e., did they intermarry into the nearby Indian tribes?) There's also some discussion by the earliest European explorers that the Cherokee and related tribes had a more "civilized" look, which in their parlance was basically a way of saying they had Europeanized features and lighter skin. Again, could this be the genetic influence of an earlier non-Indian population?
So where's our casino?