Rockfall in Mystery Canyon
September 20, 2014
At the 2014 Zion Canyon Rendezvous, I had my canyon leadership abilities tested for the first time under a stressful situation.
We were in Mystery Canyon, a canyon that is beginner friendly with competent leadership. I was with a group of 4 other canyoneers – all of whom were fairly new to the sport. There was also a group of three canyoneers that day and we had been leapfrogging each other during the approach hike and through many of the rappels.
We went through the first narrows section, saw clouds were starting to form overhead, and realized there was a chance we would see rain in the afternoon. We continued down canyon, swam through the lake, went up and over the dam, and were at the top of the Mystery Springs rappel when the world darkened and the monsoonal rain started pouring in.
We made the decision to go back up canyon a little to a section that was quite high, had large trees and seemed like a generally safe spot. To get to it, though, we had to climb up a dryfall with a log propped up to help. All but the last few of us were up when the people up to started shouting that the flood waters were coming and we had about 30 seconds. Instinctively, I ran up to higher ground and waited, waited, waited. Nothing is happening. I climbed up the dry fall and saw what I guessed they were referring to: a small, shimmering little cascade coming down the south face of the canyon. I remember thinking that it was significantly less water than the Great White Icicle – like a foot wide and less than an inch deep. We made our way to higher ground, pulled out our jackets/space blankets, and started waiting.
I should note that there was never a point in time that I didn’t feel our group was perfectly safe. We had passed the dam, the hard rain only lasted a few minutes, and there was plenty of higher ground.
Ten or so minutes later the "wall" of water finally came. If I had been a mouse stuck at the bottom of the canyon, I would have been terrified. It was definitely a wave, but no more than a few inches. It crawled slowly along, meticulously filling each pool and crack it came across before moving on to the next one. At its highest, I don’t think it was ever more than a foot wide in the narrowest sections.
After 20 minutes or so it was down to a trickle, and another 20 minutes after that we figured it wouldn’t get any worse so we started back down the canyon.
As the last few of us were making our way down the log, I also got to experience my first landslide.
I was at the bottom of the down climb with the log spotting someone coming down when I heard it. At first I thought it was more thunder, but quickly realized what it really was.
Instinctively, I pressed myself up against a big boulder with a small overhang, hoping that would be enough to save me if the landslide overcame me.
My friend Corey was at the top providing meat anchor for a hand line when he heard it. He initially thought it was a wall of water. He turned around and intended to start running up hill when he saw the rocks starting to fill the canyon bottom. Fortunately, he and everybody else was a safe distance from the landslide. After everything had settled, I took a quick look and saw that the canyon bottom was now a few feet higher. Corey pointed out a spot on the cliff three or four hundred feet up where the rocks started falling. He noted that this was right above where we had been just 10 minutes earlier and if it had fallen then, people would have been injured or killed.
I no longer felt "perfectly safe" and we hurried out of that section and finished the rest of the canyon without incident.
I made a few observations that may help others who are in a similar situation in the future. We were initially right at the Mystery Springs rappel and were all clipped in to the traverse line over the cliff. It was high enough and far enough away from the watercourse that I felt comfortable, but others didn’t and that’s why we chose to move. We ended up at a spot that was quite safe from a potential flash flood, but also in an area that has a high potential for landslides. The landslide was undoubtedly caused by the rain. Someone smarter than me can probably explain the exact cause. At the canyon bottom there were lots of landslide-sized rocks – rocks around a foot in diameter or less that were part of the cliff at one time and had fallen. Also there was a pretty big landslide in the 70s that drastically changed Mystery Canyon that was just a little up canyon from where we were.
My focus so far has been on the flash flood and landslide but I wanted to mention some of the good decisions that contributed to a successful day canyoneering. Successful in this sense means no injuries and everyone enjoyed themselves.
- We were all prepared. Everyone had a coat or something they could put on to help keep warm. Everyone brought enough food and water for the extra time we would spend in the canyon.
- Corey, though still somewhat new to canyoneering, really performed well. He has only descended a handful of canyons, but he knew how and where to help without being asked. We were able to sequence the first few rappels, he provided meat anchors on down climbs when people felt uncomfortable with them, he helped with rope management and carrying ropes, and did everything a good canyoneer should do.
- All of us were able to think rationally through the whole thing. I am not a person who makes good decisions under pressure unless I have trained for a similar situation. Consequently, I have spent a considerable amount of time taking courses, practicing in my free time, and researching situations that occur in canyoneering. Because of this training, I was able to assess the situation and logically deduce that we had little to worry about. We were safe, and I knew it. This provided me comfort and I did what I could to ease the tension others were experiencing by offering my reassurance and being light-hearted about the situation.
Anyway, the moral of this story to be prepared for any situation when canyoneering, whether that be through training or by some other means. Also, when finding higher ground in anticipation of a flash flood, if possible, find a place that has a low probability of a landslide.
As a side note, this was the third day of the rendezvous. We had all been watching the weather and every day thus far had turned out beautifully. There were around a dozen groups from the rendezvous who went through canyons that day and I am not aware of a single group who backed out because of the weather.
I also don’t know of any other group who experienced monsoonal rain. Talking to a group who did Behunin that day, they said they got to see a beautiful little trickle of water come down through the canyon. The group in Englestead didn’t experience anything, either.