Sand dunes dominate the landscape in the North Algodones Dunes Wilderness Area.
BLM
U.S. DEPARTMENT OF THE INTERIOR
BUREAU OF LAND MANAGEMENT
Cosumnes River Preserve Rafting on Merced River South Fork American River Canyon Cronan Ranch Flannel Bush Flower
California
BLM>California>Mother Lode>River Recreation>International Scale of River Classifications
Print Page
Folsom Field Office

 International Scale of River Difficulty

 

CLASS I

EASY- Waves small; passages clear; no serious obstacles.

CLASS II

MEDIUM - Rapids of moderate difficulty with passages clear.
Most open canoeists should never tackle anything tougher than class II.

CLASS III

DIFFICULT - Rapids are longer and rougher than class II. Waves numerous, high, irregular; rocks; eddies; rapids with passages clear though narrow, requiring expertise in maneuver; scouting usually needed. Requires good operator and boating equipment.

CLASS IV

VERY DIFFICULT - Rapids are generally longer, steeper and more heavily obstructed than class III rapids.  Waves powerful, irregular; dangerous rock; boiling eddies; passages difficult to scout; scouting mandatory first time; powerful and precise maneuvering required. Demands expert boatman and excellent boat and outfit.

CLASS V

EXTREMELY DIFFICULT - Exceedingly difficult, long and violent rapids, following each other almost without interuption; riverbed extrememly obstructed; big drops; violent current; very steep gradient; close study essential, but often difficult. Requires best man, boat, and outfit suited to the situation. All possible precautions must be taken.

CLASS VI
or U

UNRUNNABLE  ! ! !