If livestock grazing on federal lands is found to degrade a wild and scenic river’s water quality or outstandingly remarkable values, what steps must the river-administering agency take?

The river-administering agency must take the actions necessary to remedy adverse impacts and/or show measurable progress in addressing identified adverse effects. The Wild & Scenic Rivers Act gives river-administering agencies authority to adjust or eliminate livestock grazing, or any other commercial use, if doing so is necessary to meet the protection and enhancement standard.

Source
Interagency Wild & Scenic Rivers Council