What organization assigns the Class designations for rivers?

Question

I need to know who is in charge of assigning the Classes to rivers. Classes that tell how difficult the river is to whitewater raft.

Answer 1

The American Whitewater Association

The first link is a U.S. map where you can click on your state and it lists all the associated rivers/classes.

Blurb from the 2nd link below:

American Whitewater promotes paddling safety, publishes reports on whitewater accidents, and maintains the internationally recognized American Whitewater Safety Code. This safety code includes the International Scale of Whitewater Difficulty, the class I-V rating system for whitewater rivers that was developed by our membership in the 1950’s. Today this system is widely used by paddlers and safety personnel throughout the world. For important safety updates and additional safety resources check out our

Answer 2

American Whitewater