Native American Tribal Recognition
Directories of Tribes (NILL) includes a link to the list of federally reconized tribal entities and state recognized tribes as well as directories of tribal governments and reservations.
Bureau of Indian Affairs Federal Acknowledgement Decision Compilation v 2.0 & v 1.2 converted and posted by Indianz. And Recent Acknowledgment Actions published by the Department of Interior. See article 1 & article 2 about these databases.
"The database is an online version of the Acknowledgment Decision Compilation (ADC), a record of documents that the Bureau of Indian Affairs has on file for dozens of groups that have made it through the federal recognition process."
Code of Federal Regulations - (U.S. Government Printing Office). Title 25, part 83: Procedures for Establishing that an American Indian Group Exists as an Indian Tribe
"Primer on Federal Recognition and Current Issues Affecting the Process." Prepared for NCAI Winter Session, February, 2001. Updated November 21, 2011. Jennifer P. Hughes, Esq; Morisset, Schlosser & Jozwiak.
Indian Issues: Improvements Needed in Tribal Recognition Process. GAO-02-49 (November 2, 2001). Government Accountability Office.
Indian Issues: Basis for BIA's Tribal Recognition Decisions Is Not Always Clear - GAO-02-936T (September 17, 2002).Government Accountability Office.
Procedures for Reestablishing a Formal Government-to-Government Relationship with the Native Hawaiian Community. Department of Ineterior. Includes a link to the official copy in the final rule in the Federal Register as well as other associated documents on this topic.
Alexa Koenig. "Federalism and the State Recognition of Native American Tribes: A Survey of State-Recognized Tribes and State Recognition Processes Across the United States" 48 Santa Clara Law Review 79 (2007)