© Christopher Earls Brennen

ACA Ratings

American Canyoneering Association Ratings

Since most of adventures described in this collection involve canyoneering and since it is valuable to provide as much information as possible on the technical difficulty of each adventure, an American Canyoneering Association (ACA) Rating is provided with each account. A description of these ratings can be found at the American Canyoneering Association website, specifically at the ACA Ratings System webpage or in Tom Jones' Canyoneering site under Ratings.

A rating begins with a number from 1 to 4 signifying the following:

  1. Canyon Hiking. Non-technical; no rope required. May involve some easy scrambling requiring the occasional use of hands for balance and support.
  2. Basic Canyoneering. Scrambling, easy vertical or near vertical climbing and/or down-climbing requiring frequent use of hands. Rope recommended for hand lines, belays, lowering packs and possible emergency use. Exit and/or retreat possible without ascending fixed ropes.
  3. Intermediate Canyoneering. Exposed technical climbing. Down-climbing could be difficult and dangerous; most people will rappel instead. Rope required for belays and single-pitch rappels. Obvious natural or fixed anchors. Retreat up canyon will require ascending fixed ropes. Basic pothole escape techniques (i.e. partner assist, counter-weights) may also be required.
  4. Advanced Canyoneering. Route may involve any combination of the following: 1) difficult and exposed free climbing and/or down-climbing, 2) climbing using direct aid, 3) multi-pitch rappels, 4) complex rope work (i.e. guided rappels, deviations, rebelays), 5) obscure or indistinct natural anchors, 6) advanced problem-solving and anchor-building skills.

This is followed by a letter indicating how wet the hike may be:

  1. Normally dry or very little water. Dry falls. Water, if present, can be avoided and/or is very shallow. Shoes may get wet, but no wetsuit or drysuit required.
  2. Normally has water with no current or light current. Still pools. Falls normally dry or running at a trickle. Expect to do some deep wading and/or swimming. Wetsuit or drysuit may be required depending on water and air temperatures..
  3. Normally has water with strong current. Waterfalls. Expect to do some deep wading and/or swimming in current. Wetsuit or drysuit may be required depending on water and air temperatures.
Note that the water level in any canyon can fluctuate greatly from year-to-year, season-to-season, even day-to-day. If, upon arrival at a canyon, you discover the water volume/current is greater than indicated by the rating, descent will be more difficult. It will be necessary to reevaluate your decision to attempt the descent.

The third symbol, either the letter R or X, is optional and is used to designate unusual risks:

Note that the presence of an R or an X in a rating suggests that the canyon will involve higher than average risk. The absence of an R or an X does not suggest that there will be no risk. All canyoneering involves risk. Risk factors include number and frequency of rappels, length of rappels (single- or double-rope) and exposure, anchor availability, anchor quality, route finding, obstacles, problem-solving, terrain encountered between technical sections, flash flood potential, availability of exits and high ground, water temperature, prolonged immersion, and difficulty of evacuation or rescue.

The last alphanumeric symbol is a Roman numeral indicating the time duration of the hike:

  1. Short. Normally requires only a couple of hours.
  2. Normally requires a half day.
  3. Normally requires most of a day.
  4. Expected to take one long, full day. Get an early start. Bring a head lamp. Plan for possible bivy.
  5. Expected to take an average one and a half days.
  6. Expected to take two or more days.
Note that time estimates are based on average group of 6 people or less. Larger groups and less experienced groups will take longer. An accurate self-assessment of your abilities will be important. For some users, it may be adequate to refer to time in terms of half day, full day or multi day. Others may prefer a more specific estimate and choose to use the Roman Numeral Grade system common in traditional multi-pitch rock climbing.

Finally, I have followed the example of Tom Jones and added an expression of my own enjoyment of each of the hikes by attaching one, two or three stars:

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Last updated 3/10/04.
Christopher E. Brennen