49 C.F.R. § 29.202
How does a Tribe submit a final offer?
(a) A Tribe must submit a written final offer to the Self-Governance Official to [email protected] or send the final offer using any other method that provides receipt to: Self-Governance Official, U.S. Department of Transportation, Office of the Secretary, Office of the Assistant Secretary for Governmental Affairs (I-10), 1200 New Jersey Avenue SE, Washington, DC 20590.
(b) The final offer should be a separate document from the compact, funding agreement, or amendment and clearly identified as a “Final Offer—Response due within 45 days of receipt.”