Here are the materials in Picayune Rancheria of Chukchansi Indians v. Dept. of Interior (E.D. Cal.):
IGRA two-part determination
Briefs in United Auburn Indian Community v. Brown — Authority of Governor to Concur in Two-Part Determination
In the California Supreme Court, here:
Lower court decision here.
Two part determination letter here: BIA Letter.
California COA Affirms Authority of Governor to Concur in Two-Part Determination
Here is the opinion in United Auburn Indian Community v. Brown.
Here is the unpublished opinion in Citizens for a Better Way v. Brown.