ACA Canyon Rating System American Canyon Association
NOTE: Ratings refer to descents in normal conditions, during what is considered the normal season for the canyon. Adverse conditions, such as higher than normal water volume or colder temperatures, will increase the difficulty of the descent.
Technical CanyoneeringNever enter a semi-technical or technical canyon without the knowledge and skills needed to safely explore and return. Many technical canyons, such as Das Boot, also require gps skills or excellent map reading skills. Remember slot canyons of any difficulty can change dramatically in a short time. Do take classes and travel with those who have gained experience. Use quality equipment in the canyons because you life can depend on it. Always wear a helmet, keep hair up and away from rapel devices! A ponytail won't do because the whole ponytail can get caught and then you are in danger.
1 Canyon Hiking - Non-technical hiking where no rope is required. There might be some scrambling requiring the use of hands.
2 Basic Canyoneering - Rope recommended for belays, rappels and possible lowering packs and possible emergency use. Basic canyon scrambling, easy vertical or near vertical climbing and down climbing requiring frequent use of hands.
3 Intermediate Canyoneering - Exposed technical climbing. Down climbing could be difficult and dangerous where most people rappel instead. Rope required for single-pitch rappels and belays. Anchors are usually existing. Retreat up canyon will require ascending fixed ropes. Basic pothole escaping.
4 Advanced Canyoneering - Includes difficult and exposed climbing, down climbing, multi-pitch rappels, complex rope work, anchor problems, advanced problem solving.
A - Normally the canyon is dry or holds little water.
B - Normally the canyon holds water but the current is light or there are still pools. There might be a trickle on the falls, water deep enough that needs to be waded or swam. Wetsuit or drysuit may be required depending on temperatures.
C - Normally the canyon contains water with strong current and even waterfalls. Swimming deep pools required. Wetsuit or drysuit may be required depending on temperatures.
I Requires only a couple of hours.
II Requires a half day.
III Requires most of a day.
IV Dawn to dark and longer if problem arise. Bring a head lamp and plan for possible bivy.
V Expected to take an average 1.5 days.
VI Expected to take two or more days.
Zion National Park, Utah
History of the Thunderbird
This is my new favorite quote:
"I don't know who Tanya Milligan is, but I mean www.zionnational-park.com
It's a better site than the NPS's anyway."
Written by the authors of the book: Favorite Hikes in and around Zion National Park