S. 3129 would designate segments of the Gila River system in New Mexico as components of the National Wild and Scenic Rivers System and transfer land from the Gila National Forest to the Gila Cliff Dwellings Monument. CBO estimates that enacting S. 3129 would not affect direct spending or revenues. CBO has not estimated the discretionary costs of implementing the bill. The bill contains no intergovernmental or private-sector mandates as defined in the Unfunded Mandates Reform Act.