Mandans?
I've read that Thomas Jefferson ordered Lewis & Clark not to mention one word about light-skinned, blue eyed Indians in their written scouting report to him.
His concern was that some other European power would use that 'hook' to claim those areas that were not yet part of the USA. So....
There’s record of blue eyed Natives east of the Cherokee regions. The largest tribe in the Piedmont spoke Algonquin. There is some speculation that the failed colony at Roanoke Island provided a blue eyed gene.
Didn’t some of them also have red hair?