River Classifications

Sections of rivers are classed on the International Scale of River Difficulty from easiest (Class I) to extremely difficult and dangerous (Class VI).

• The classifications are based upon gradient, volume, river features, constrictions, and numerous other factors.
• Classes of a river can change based upon specific locations on the river. For example, one section of a river may be Class I while just around the bend, the river may turn into a Class IV drop.
• River classification can increase or decrease due to water volume fluctuations and water temperature. Therefore, use the scale as a general guide.
• For additional information, see the “Safety Code of American Whitewater” on the American Whitewater website. Note that this information is geared toward the paddling community.