Conversation so far:
What about William Henry Dietz heritage was contested?
Dietz's heritage was first contested in 1916 after former neighbors who settled on the Pacific Coast heard he was posing as an Indian.
Was William Henry Dietz living on an Indian reservation or had he lived on one before?
It is not confirmed whether William Henry Dietz actually was born on the Pine Ridge reservation in South Dakota or not.
Who was William Henry Dietz impersonating when the FBI investigated him?
The Bureau found William Henry Dietz had taken on the identity of James One Star.
Did William Henry Dietz do any jail time for the identity fraud?
William Henry Dietz ended up with a 30 day sentence in the Spokane County Jail after he pleaded no contest.
Did William Henry Dietz have any other Indian brothers and sisters from the mother that testified for him?
Where was the trial for William Henry Dietz's fraud held?
William Henry Dietz was tried in Spokane, Washington in June 1919 for the first offense.
Was William Henry Dietz married to anyone else during this time?
After Angel De Cora died in 1919, he married Doris O. Pottlitzer

Question: What tribe was he claiming to be a member of?
Self-contained rewrite: What tribe was William Henry Dietz claiming to be a memeber of?