Arbitration, Choice of Law, Tribe Law
Loan agreement arbitration clause electing the forum and law of the Sioux nation is invalid and unenforceable, as it operates as a waiver of all federal rights.
Not severable from arbitration provision.
No need to exhaust tribal remedies, as the controversy has nothing to do with the tribe.
http://www.ca4.uscourts.gov/Opinions/Published/151170.P.pdf
Since 2011. An occasional commonplacing of the U.S. Circuit Courts of Appeal.
Neither an authoritative statement of the law nor legal advice. Quick work.