I’m always amazed at the number of blonde haired, blue eyed Indians I see.
You have apparently been to Oklahoma, and met a great many Cherokees.
My two grandsons match that description (though light brown hair is more accurate). Their great grandmother was a card holding member of the tribe. In their tribe, membership is passed down based on parentage membership, not blood content. Tribal membership has been passed down with each generation. Their mother is 1/8th, they are both 1/16th, but legally they are tribal members.
My sisters were the same.
My grandmother was Pottawatomie...Dark hair and dark eyed. A couple of my Aunts went to Chilocco Indian School....My Aunt Virginia met her husband my Uncle there...He was full blood Creek....
https://en.wikipedia.org/wiki/Chilocco_Indian_Agricultural_School
I'm actually by marriage related to Jim Thrope.
I can trace my Indian family back to the mid late-1800's...The rolls before that...were difficult. As Pottawatomi names changed during their lives...and bands got factured..over the years.
There are three bands...The Forest Band, The Prairie Band...and the Citizen Band.
FWIW-