Perhaps a DNA test? You might try to ask the tribal elders what to do.
The above is not intended to be legal advice, but may be used for general information. Please contact an attorney for specific help tailored to your needs. www.figgardenlaw.com
You can get a paternity test using paternal relatives if they are available if there is no available DNA sample (sometimes hospitals or coroners keep them, or they can be extracted from old letters, hairbrushes etc) and none can be obtained by an exhumation. But a paternity action in Ohio can only be filed before age 23 so if you're older than that you may need to investigate whether there's a tribal procedure to establish paternity, and what those requirements would be.
For informational purposes only; not intended to, and does not, constitute legal advice or a legal opinion.