International Scale of Rapids

Whitewater rapids are rated on a scale of I (very easy) through VI (life threatening), indicating the level of difficulty of each rapid at medium water level. Remember that the nature of a particular rapid can change dramatically as river flows and water levels fluctuate. Be sure you know how to read water and scout rapids from the shore, if necessary, to find the safest route.
  Class I - Very Easy
  Class II - Easy
  Class III - Medium
  Class IV - Difficult
  Class V - Very Difficult
  Class VI - Life Threatening

Class I
Very Easy - Small, regular waves and riffles, few or no obstacles, little maneuvering required.

Class II
Easy - Small waves with some eddies, low edges, slow rock gardens, moderate difficulty, some maneuvering required.
Class II rapids on the Lower Deschutes include:
  Upper Trout Creek Rapids
  Lower Trout Creek Rapids (II+)
  Four-Chutes Rapids
  Surf City Rapids (II+)
  White River Rapids (II+)
  Upper Elevator Rapids
  Lower Elevator Rapids (II+)
  Trestle Hole Rapids (II+)
  Bull Run Rapids
  Jet Pump Rapids (II+)
  Harris Rapids
  Green Light Rapids (II+)
  Free Bridge Rapids
  Knock-Knock Rapid

Class III
Medium - High and irregular waves, strong eddies, narrow but clear passages that require expertise in maneuvering, scouting from the shore is recommended.
Class III rapids on the Lower Deschutes include:
  Whitehorse Rapids (III+)
  Buckskin Mary Rapids
  Wapinitia Rapids
  Box Car Rapids
  Wreck Rapids
  Washout Rapid
  Gordon Ridge Rapids
  Colorado Rapids
  Rattlesnake Rapids
  Moody Rapids

Class IV
Difficult - Long rapids with powerful irregular waves, dangerous rocks, boiling eddies, precise maneuvering and scouting from the shore is imperative, take all possible safety precautions.
Class IV rapids on the Lower Deschutes include:
  Oak Springs Rapids 

Class V
Very Difficult - Long rapids with wild turbulence and extremely congested routes that require complex maneuvering, a danger to your life and boat, near the limits of navigation.
No Class V rapids are noted on the Lower Deschutes River.

Class VI
Life Threatening - The limits of navigation, rarely run, a definite hazard to your life.
  Sherar's Falls is the only Class VI rapid on the Lower Deschutes River.  MANDATORY PORTAGE FOR ALL BOATERS.