What is the responsibility of the federal study agency for a river identified for study under Section 5(d)(1) of the Wild & Scenic Rivers Act and found eligible, pending a suitability determination?

Once such a river has been found eligible, the federal study agency should, to the extent it is authorized under various laws and subject to valid existing rights, ensure the river and the surrounding area are protected as a potential wild and scenic river pending a suitability determination.

Source
Interagency Wild & Scenic Rivers Council