25 C.F.R. § 1000.1135
What happens if the Secretary takes no action within the 60-day period (or any extensions thereof)?
The final offer is:
(a) Accepted automatically by operation of law for a compact or funding agreement provision except as to its application to a program described under 25 U.S.C. 5363(c); or
(b) Rejected automatically by operation of law with respect to any program described under 25 U.S.C. 5363(c).