River Ratings System
Rivers are rated by the most difficult rapids which appear on a particular run. A plus
sign (+) after a rating indicates there may be one or more rapids with difficulty slightly
above the level indicated. A river's level of challenge can change greatly with
fluctuations in water levels. The ratings listed for the rivers on this web site are at
the typical flows run through the rafting season. The actual water
level on your trip may be higher (or lower) and the river correspondingly more demanding.
If a trip cannot be run with a reasonable assurance of success, we will, with as much
advance notice as possible, allow trip members to choose between a different river on the
same date, or the same river on a different date.
Class I. Easy.
- Waves small, passages clear; no serious obstacles.
Class II. Medium.
- Rapids of moderate difficulty with passages clear.
Class III. Difficult.
- Waves numerous, high, irregular; rocks; eddies; rapids with passages clear though
narrow, requiring expertise in maneuvering. Rivers include: Cache Creek, South Fork
American, Lower Klamath, and the Rogue.
Class IV. Very Difficult.
- Long rapids; waves powerful, irregular; dangerous rocks; boiling eddies; powerful and
precise maneuvering required. Rivers include: Lower Kern, Upper Kern, Kaweah, Merced,
North Fork Stanislaus, Tuolumne, Middle Fork American, North Fork American, Lower North
Yuba, and the Upper Klamath.
Class V. Extremely Difficult.
- Exceedingly difficult, long and violent rapids, following each other almost without
interruption; riverbed extremely obstructed; big drops; violent currents; very steep
gradient. Paddlers must pass the Class V Paddler's Test, and have prior Class IV or better
whitewater experience, preferably with Whitewater Voyages. Rivers include: Thunder Run
(Kern River), Upper Kern Combo, Forks of the Kern, Cherry Creek / Upper Tuolumne, Upper
North Yuba, Giant and Generation Gap, California Salmon, and Burnt Ranch Gorge.
Class VI. Unrunnable.
- Just like it says - Don't even think about it!
- Boats must be carried along the river bank to get around an unrunnable stretch of river.