7 Things You Actually Can Do to Reduce the Risk of Rockfall

Rockfall is a natural hazard in the sport of rock climbing—a severe, potentially life-threatening risk in an already hazardous sport. Climb long enough, and you’ll collect scary stories of falling rocks, if you’re lucky enough to walk away from them.

One of my own stories stems from September 2023, deep within the belly of the North Chimney on Colorado’s Longs Peak. My partner and I were the first party in the Chimney that morning, simul-climbing by headlamp to approach the Black Dagger route on the Diamond. Suddenly, we heard panicked calls from other climbers above us. Their screams echoed across the cirque: “ROCK, ROCK, ROCK!”

Sure enough, I heard a rock come whistling down and explode against the wall beside me. In the darkness, I never even saw the rock. But I could smell the acrid odor created by the intense collision of stone against stone.

Why do rocks fall?

I asked a geological and geotechnical engineer, Anna Ristuccia, this question: “Why do rocks fall?”

Ristuccia’s expert answer? “Gravity drives it, but gravity alone isn’t enough to initiate it. What you need is a failure plane in the rock mass and a deteriorating bond between the fragment of rock and the larger rock mass. In most cases, weathering (chemical and/or mechanical) plus gravity is the magic combo that makes rocks fall. In some cases, rain, snowmelt, or some other water source—or human (or animal) activities—might also be to blame for rockfall.”

Defining the hazard

The USGS defines rockfall as “abrupt movements of masses of geologic materials, such as rocks and boulders, which become detached from steep slopes or cliffs. Separation occurs along discontinuities such as fractures, joints, and bedding planes, and movement occurs by free-fall, bouncing, and rolling.”

Hazards, like rockfall, exist at all times and can occur at any time. This is true even if we climbers have not personally experienced it. However, when we expose ourselves to the hazard, it becomes a risk. It’s up to us to mitigate the risk to the best of our abilities.

What spikes rockfall risk?

Issue 78 of the Accidents In North American Climbing 2025, published by the American Alpine Club, reported eight rock climbing accidents involving rockfall in 2024. According to editor Pete Takeda, eight rockfall incidents is around average.

Takeda added that in some years, reported rockfall-related accidents involve “particularly alarming” outcomes or circumstances. For example, in 2023, he recalls three situations where a bystander at the base of a crag was struck by rockfall. Two of those incidents ended up being fatal. And both of the bystanders who died were wearing helmets. “So you can be standing at a crag, minding your own business, even wearing a helmet, and still get killed,” Takeda shared with me.

While every accident is unique and some level of rockfall risk will always exist, there are some strategies you can deploy to mitigate the threat.

Understand what creates rockfall events

First, familiarize yourself with what commonly triggers rockfall in the first place. Some causes of rockfall include:

• Mechanical weathering: Freeze/thaw cycles, plant growth in cracks, windstorms
• Chemical weathering: Water reacting with rock to change its composition into a more easily eroded material
• Humans and animals: Walking and climbing around steep, rocky terrain
• Excess water: Rainfall, snowfall, and irrigation water can lubricate rock joints and fractures
• Erosion: Rivers, glaciers, debris flows, and human-related activities create erosion

Consider the terrain

Before researching rockfall for this article, I thought certain rock types could be sketchier than others. However, assessing rock isn’t binary (i.e., granite is good, sandstone is sketchy).

Ristuccia, the geological and geotechnical engineer, corrected me. She explained that all rock types are susceptible to rockfall. “Highly jointed rock faces, rock faces that deteriorate into talus/scree fields, soft rocks, and rocks with a lot of layers” are more susceptible to breakage, according to Ristuccia. If you see those warning signs, the rock can break and fall, regardless of the rock type. That’s true for all rock types we climb on, from the mega-hard quartz conglomerate in the Gunks to sandstone spitters in the Creek and Yosemite’s granite.

Avoid periods when rockfall risk rises

Rockfall events cluster around certain seasons and weather. “Generally speaking, rockfall is more common during times of the year when freeze-thaw cycles are active,” Ristuccia explained. She added that ice wedging, a phenomenon wherein water freezes in cracks overnight, can exert immense pressure on the rock and “slowly wear away and break the rock mass down, leading to rockfall.” That’s why I avoid some cliffs in the spring up by me in the Northeast after a cold winter.

Moisture doesn’t only increase risk during freeze-melt cycles. “Rain and significant weather events can also destabilize tenuously attached rocks and drive rockfall,” Ristuccia says, “so following storms is another time I’d be extra careful.”

Since humans can also trigger rockfall, it’s also critical to consider timing your climb around other parties in your risk assessment. Following a congo-line of parties up a classic route is a surefire way to expose yourself to rockfall. Even hanging around the base of a busy sport crag exposes you to hazardous rockfall.

How to mitigate rockfall risk as a climber

Wear a helmet

We have to start with the obvious one. Even though you yourself may not drop a rock on your own head, as a climber and belayer, you’re still exposed to rockfall at all times. So, to mitigate the severity of a rockfall-related head injury, wear a helmet. Even then, a helmet might not completely prevent injury or death, depending on the size of the rock.

Be careful where your rope goes

As climbers, we spend a lot of time trying to avoid triggering rockfall with our hands and feet. However, we often forget that our rope can also cause rockfall.

The rope should be treated as an extension of your body and should be cared for when moving over loose terrain. You can set a directional to elevate the rope off the ground. When rapping, you can saddlebag your ropes or flake them into a backpack to prevent them from dislodging loose material on the way down.

Here’s an example of what I mean:

Observe and test the rock

Solid, bomber stone gives me the warm-and-fuzzies. On the other hand, bad rock gives me the heebie-jeebies. To decipher good from bad, always remain vigilant and assess and test the rock when necessary.

Vigilance is especially pertinent on long multi-pitch routes and in alpine environments, where rock quality can vary widely.

Red flags for bad rock include:

• Cracks on all sides of a single feature
• Hollow sounds and/or vibration when you knock it
• Thin flakes and loose blocks
• Chalk-marked X’s

Avoid the X’s

In climbing, X does not mark the spot. If you see features marked with an X in chalk, that means the integrity of the feature is suspicious, and you should avoid using it. If you encounter a death flake or loose block yourself when climbing, mark it with an X to help keep future climbers safe on that route, too.

How to mitigate rockfall risk as a belayer

Here are some tips for belayers—or anyone hanging out at the crag—to be less at risk in the event of rockfall.

Wear a helmet

Helmets are vital pieces of personal protection equipment. They cannot prevent rockfall, but they can mitigate the severity of a rockfall-related head injury by acting as a shield for your skull. So, when a rock falls when you’re belaying, don’t look up. Instead, keep your head centered above your shoulders, helmet facing up for maximum protection.

Shelter toward the wall, not away

Every rock falls differently. In the text “Practical Rock Engineering,” mechanical engineer Evert Hoek writes, “Once movement of a rock perched on the top of a slope has been initiated, the most important factor controlling its fall trajectory is the geometry of the slope,”

In my experience, most rocks fall, smash into the wall, and catapult away from the base of the cliff. That’s why, sometimes, it may be best to shelter as close to the wall as possible when a rock falls instead of trying to run away.

In this helpful American Alpine Club reel shared last spring, Takeda (the editor of Accidents in North American Climbing) explains why:

Stay focused

If you remain focused while belaying, you’ll see the rock the minute it gets dislodged. Immediately understanding the trajectory of the object is extremely useful for deciding the severity of the rockfall event and where to position yourself.

Debriefing my close call with rockfall

Despite planning to be “first” in the Chimney that morning, it turned out, a party was already above us on Broadway Ledge. Unbeknownst to us, they rappelled into the cirque from the Chasm View rappels and caused a rock to fall into the Chimney.

Fortunately, we had our helmets on. And when I heard the scream, “ROCK,” I tucked myself into a small alcove in the rock. Luckily, we got away uninjured. However, the other potentially deadly outcome of the rockfall event still sticks with me to this day. And yes, we sent our route.

Teddy Dondanville is an Assistant Rock Guide with the American Mountain Guides Association and a Wilderness First Responder based in upstate New York. 

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