What is the definition of “outstandingly remarkable value?”

In the Wild & Scenic Rivers Act, river values identified include scenic, recreational, geologic, fish and wildlife, historic, cultural, or other similar values. The Wild & Scenic Rivers Act does not further define outstandingly remarkable values. However, agency resource professionals have developed interpretive criteria for evaluating river values (unique, rare, or exemplary) based on professional judgment on a regional, physiographic, or geographic comparative basis. (Refer to The Wild & Scenic River Study Process (1999).)