Mountaineering Accident Statistics

Mountaineering Accident Statistics

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The American Alpine Club annually publishes Accidents in American Mountaineering, which contains reports from various mountaineering accidents that occurred that year. The journal also includes statistical tables which summarize the number of mountaineering accidents, injuries, and fatalities, as well as interesting specifics such as terrain, immediate and contributing causes, ages and experience levels of individuals, month of year, type of injury, and location. I was fascinated by these statistical tables, but found the data hard to visualize. So, I spent a day creating pie charts and graphs from the 2007 Statistical Tables, which contain statistics on mountaineering accidents from 1951-2006 (click the above link to see the raw data for the 2007 statistical tables, which were the most recent I could find on the AAC website). The following page gives my graphical output of the statistical tables. I also draw a few inferences from the data.

Keep in mind that statistical studies involve some degree of personal interpretation/presentation, simplification of scenarios, and biased data, so all of my deductions should be taken with a grain of salt. Also keep in mind that a percentage of mountaineering accidents are never reported. Inherent to nearly all statistical data, the "missing data" issue tends to make absolute values a bit too low, but has little effect on percentages or relative comparisons.

My overall conclusion: For your best chances at experiencing a mountaineering accident, try climbing unroped or above your abilities on rocky terrain sometime between May-Sept in California or Washington.

"To reduce the chance of an accident, competent climbers develop a balanced relationship with fear, an awareness of danger, and turn their mental energy into positive means to overcome problems. Both instinct and acquired judgement are developed from experience. One learns about choices, when to push limits, where to avoid stonefall, where to belay, and when to turn back."

"Climbing is never wholly predictable, and from this uncertainty a richness may arise. It is important not to diminish the spirit of climbing and eliminate all risk. To reduce all commitment lessens the spirit and engagement of the adventure."

-Sage advice from the climbing great Fred Beckey, Fred Beckey's 100 Favorite North American Climbs

1951-2006 Mountaineering Accidents, Summary Graphs

Mountaineering Accidents, Injuries, Fatalities 1951-2006:
Injuries and Deaths per Accident, 1951-2006

Mountaineering Accident Details, 1951-2006 Averages

Primary Cause
Contributory Cause
Type of Injury
Experience Level
Age of Individuals

Mountaineering Accidents by Location, 1951-2006 Averages

The statistical report contains a table listing the accidents by location. I took the opportunity to plot this data on cartograms, which are a great way of plotting geographical data in a way that highlights geographical trends. The following cartograms are broken down by decade to show how the number of accidents and fatalities has evolved over the last half-century. (If you are interested in cartograms, click here to go to my cartograms page that gives several more cool cartogram examples, as well as explains how they work, how I make them, and some background behind them.)

Some interesting trends in the pie charts and cartograms below:
  • Most mountaineering accidents occur in the rugged mountainous states of Washington, California, Wyoming, Colorado, and Alaska; of these states, Washington and California have the highest number of mountain accidents. A likely reason why these states have the most mountain accidents is because they not only have the greatest area of climbable terrain, but they also have a high number of "trophy" peaks (such as Denali, Rainier, Half Dome, etc.) which attract an outsized proportion of non-locals who are often overly eager to get to the summit.
  • Most mountaineering fatalities also occur in the five states mentioned above, with Washington and California having the highest numbers. In addition, Oregon also has a significant number of fatalities (even though it does not stand out as having as high a rate of accidents); these fatalities likely due to the fact that Mt. Hood seems to have a fair number of fatal accidents a year.
  • When normalized by state population, most mountaineering accidents per capita occur in Wyoming and Alaska. California in particular has a much smaller accident per capita rate than total accident rate.
  • When normalized by state population, most mountaineering fatalities per capita occur in Alaska and Wyoming. California in particular has a much smaller fatality per capita rate than total fatality rate.
  • The highest number of accidents and fatalities occurred in the 1970s and 1980s, especially in Washington and California. This was a time when new routes were being put up and new terrain was being explored.
  • Alaska has progressively had a greater percentage of the nation's mountaineering accidents and fatalities. This is likely due to an increase in Alaskan climbing as well as in increase in the proportion of accidents being better reported (although I still suspect a rather significant percentage of mountain accidents go unreported in Alaska compared to other states).
  • There has been a slight increase in the proportion of accidents that occur on the Atlantic-North coast over the years. This could indicate an increase in activities such as cragging, skiing, and ice climbing.
There are surely other interesting trends I have not mentioned. So feel free to study the following pie charts and cartograms and develop some more interpretations!

Note that this data does not allow a direct conclusion that one state is safer to climb in than another. For example, are there more accidents in Colorado than Alaska because there are factors that contribute to more accidents or are there just more people climbing? (Probably the answer is there are just more people climbing since the mountains are more accessible in Colorado than Alaska.) In order to make that type of comparison the number of person-hours climbing in each state must be factored in, rather than just using the total number of accidents/fatalities.

Total Reported Accidents by Location, 1951-2006 Averages - Pie Chart
Fatal Accidents by Location, 1951-2006 Averages, Pie Chart

Total Reported Accidents by Location, per 1,000,000 people in state, 1951-2006 Averages - Pie Chart

Fatal Accidents by Location, per 1,000,000 people in state, 1951-2006 Averages, Pie Chart

Total Reported Accidents by Location, 1951-2009 Data by Decade - Cartograms







Fatal Accidents by Location, 1951-2009 Data by Decade - Cartograms








Comparison with Traffic Accidents, 1990-2006 data

Although not covered in the statistical tables of the American Alpine Journal's Accidents in American Mountaineering, I was interested in how the frequency of mountaineering accidents compares with the frequency of traffic accidents.

I soon discovered that it is difficult to accurately compare climbing and driving. Climbing vs. driving would be most comparable if the number of accidents could be normalized by the hours spent climbing or driving (i.e. total person-hours/year driving and total person-hours/year climbing). However, this sort of hourly data is not readily available or easily estimated (I'd estimate that I spend more time in the mountains than in my car, whereas most climbers probably drive more than climb).

So I tried another normalizing method, which involved multiplying the climbing accidents by a factor which corresponds to the fraction of climbers in the population. Assuming everyone drives, but only 1 in 150 climbs (the Outdoor Industry Association estimates there are 2 million climbers in the US, which has a population of roughly 300,000,000), then multiplying mountaineering accidents by 150 would somewhat control for exposure. Technically, this technique assumes that the typical climber spends about as many hours driving as climbing, which is probably reasonable within a factor of 2. Even when the number of climbing accidents are multiplied by the normalizing factor of 150, the statistics suggest that the act of climbing is actually safer than the act of driving by a significant margin.

My conclusion, with however large a grain of salt you want to season it with: It's more likely a climber will get in an accident driving to or from the climb than on the climb itself.

Mountaineering Traffic Comments
Accidents reported per year 135
(x150 = 20250)
6,339,200 A climber is 313 (=6339200/20250) times more likely to get in a traffic accident than in a climbing accident.
Injuries per year 111
(x150 = 16650)
3,031,800 A climber is 182 (=3031800/16650) times more likely to get injured in a traffic accident than in a climbing accident.
Fatalities per year 28
(x150 = 4200)
42,880 A climber is 10 (=42880/4200) times more likely to die in a traffic accident than in a climbing accident.
(Note that this factor considers both accident frequency and fatality rate; hence, even though a climbing accident is more likely to cause a fatality than a traffic accident, because climbing accidents are less frequent, it is still more likely a person would die in traffic than climbing.)
Injuries per accident 0.82 0.48 Although mountaineering accidents are much less frequent than traffic accidents, they are 1.7 times more likely to cause injury than traffic accidents.
Fatalities per accident
0.21 0.01 Although mountaineering accidents are much less frequent than traffic accidents, they are 31 times more likely to cause fatalities than traffic accidents.
(Traffic data from US Census Bureau, Motor Vehicle Accidents and Fatalities, 1990-2006. Mountaineering data uses 1990-2006 AAC accident statistics for consistency.)

Below is a bar graph (sent to me by my friend Clint Cummins) showing the main causes of death in the US in 1988 for age 15-44, by sex. Motor vehicle accidents is the biggest cause of death for males. Mountain accidents would be included under "other accidents," a category which likely includes a fair amount of non-mountaineering accidents such as falling off ladders, crashing motorboats, housefires, etc. Altogether, "other accidents" have about the same death rate as suicide, diseases, cardiovascular, and cancer.

(Random notes: In higher age groups, cardio, rather than motor vehicle accidents, dominates. This bar graph was created out of 1988 data, when the AIDS death rate was higher than it is now.)

A note on conditional risk

The previous section used statistics to show that climbing accidents are relatively rare in the grand scheme of things. However, it is still important to be aware of the very real dangers in the mountains. Conditionally, mountaineering can be a risky undertaking (for example, it would probably be much more dangerous to go climbing on loose rock in poor weather than to drive down a residential street mid-morning). But, for some people, the risk adds to the fun and adventure of climbing.

Cartoon by Randall Munroe, found on

Personal Accident Accounts

I've had the misfortune of being involved in two separate mountaineering accidents in Washington state. Both were caused by loose rock in rugged alpine terrain. In both cases, the climbing party was very experienced, and a series of good decisions resulted in a successful rescue. Click the links below to see the accident reports complete with photos.

Accident 1
In July 2009, my partner fell 60' and broke his femur and heel, requiring a shorthaul of the north buttress of Mt. Terror. This rescue was complicated by the fact that a second uninjured person in our party was stranded on the mountain for 4 more days when poor weather prevented him being able to be airlifted off when the helicopter returned.

Accident 2
In Sept 2010—ironically, only a week after I posted this article on accident statistics—I suffered a severe compound fracture of my tib/fib on the north face of Vesper Peak. This also required a helicopter rescue.

Mt. Rainier Climbing and Accident Statistics

I also have a separate statistical study on Mt. Rainier data, which looks at Mt. Rainier Accident and Fatality and Search-and-Rescue statistics, among other interesting data.

More on my website

This article is copied from my website, which has several other articles, climbing trip reports, and photographs from the North Cascades and elsewhere:


Post a Comment
Viewing: 1-20 of 47
Arthur Digbee

Arthur Digbee - Sep 8, 2010 7:49 am - Voted 10/10

driving and climbing

The ideal comparison might be hours climbing vs. hours driving. Another might be "a year of being a driver" vs. "a year of being a climber." Insurance companies think that way and (as we know) may charge climbers higher rates.

So, we'd want to know how many people climb. I can't find that info but did find that 22.2 million Americans go backpacking, or about 1/15. Climbers are certainly less numerous than that. So, multiplying accidents by 15 to control for "exposure" would be a start on one way to compare.


StephAbegg - Sep 8, 2010 12:55 pm - Hasn't voted

Re: driving and climbing

Thanks for pointing out this way to control for exposure. I added some numbers to the table using a factor of 50. Still safer to climb, I believe it every time I subject myself to trying to drive around Seattle.

vancouver islander

vancouver islander - Sep 8, 2010 2:40 pm - Voted 10/10

Very interesting

Especially the numbers on ascent vs descent. I had often heard that an accident during descent was far more likely. Apparently not the case.

Thanks for posting.


CSUMarmot - Sep 8, 2010 3:39 pm - Voted 10/10


great stats there, i only wish there was a cause of fatalities chart, i bet lightning would seem more substantial than in the 'primary cause of accidents'


gimpilator - Sep 9, 2010 1:42 pm - Voted 10/10

Good Stuff

I always look forward to reading your articles. Your interest in mountaineering combined with your skill in research always makes for a good read. Also, the graphical displays of information are fantastic!

I love this statement:
"I was interested in how the frequency of mountaineering accidents compares with the frequency of traffic accidents. As I've always suspected, the statistics reveal that the real danger of a climbing trip is the drive to and from the climb"

My parents are rather overprotective so I try to combat the unrealistic view of climbing which has been cast by the media with logical statements similar to yours. I've actually been comparing the danger of climbing to the danger of driving for years.


silversummit - Sep 9, 2010 7:45 pm - Voted 10/10

Food for thought....

Whenever I read an article about mountaineering accidents (or most any kind of accident) I also wonder how much goes unreported either because the group relies upon a wide variety of reporting sources or because there is no legislation requiring reporting. My gut feeling tells me that much like whitewater accidents unless officials are involved for some reason either in the rescue or as witnesses etc. or as required by law some accidents just aren't ever written down anywhere.

For example, while unrelated since it wasn't climbing, in August 2009 I slipped off a trail in Rainier NP and broke my ankle. I walked down the trail myself and tried to find first aid help but none seemed available at that hour so we drove out of the park to our chalet and took care of the injury ourselves. I will never show up as an accident for August 2009, yet I know Rainier keeps stats on all rescues, first aid given etc.

Also, I think about "near-misses" like those in airline situations. Very rarely do you read about the times someone almost got killed but was unhurt by another climber's actions climbing upward etc. Sometimes the other group of climbers never even interact with the "near miss" party.

Anyway, thanks Steph for providing much food for thought!

P.S. The Total Fatal and Reported Accident cartograms reminded me so much of deformed butterflies that I could barely get past their shapes to read them! Nothing like color and graphs to make a point!


StephAbegg - Sep 9, 2010 8:47 pm - Hasn't voted

Re: Food for thought....

Good points. I think the unreported aspect is inherrent to almost any statistical data out there, and algorithms have even been created to correct for unreported and missing data. Usually percentages (such as the pie charts) and relative numbers can be relied upon better than absolute values (which are probably a bit low).

foweyman - Sep 12, 2010 10:53 am - Hasn't voted

misleading factor of 50

Sorry, but your factor of 50 still doesn't allow for a realistic comparison of climbing and driving. As Arthur Digbee indicated the number you need is total person-hours/year driving divided by total person-hours/year climbing. Your estimate of 50 accounts for the fact that more people drive than climb but doesn't account for the different amount of time that is spent on each activity. I'm certain that the number of driving hours is much more than 50 times greater than the number of climbing hours.

Similarly, the comparison of total accidents in each state doesn't allow the conclusion that climbing in one state is safer than another etc. In order to make that type of comparison the number of person-hours climbing in each state must be factored in. The presented state-by-state statistics mostly indicate which states have the most climbing, not which are the most dangerous.


StephAbegg - Sep 12, 2010 2:43 pm - Hasn't voted

Re: misleading factor of 50

Thanks for your suggestions, which I agree with. I've revised the text of my article appropriately. I've still kept the factor of 50 for reasons I mention in the article, but mentioned that a better normalizing factor would be person-hours.


hellroaring - Sep 12, 2010 1:26 pm - Hasn't voted

what about...

just wondering where riding a bicycle thru heavy urban traffic to go cragging, climbing all day, then riding back thru heavy evening commute puts you in those stats?

Eric Sandbo

Eric Sandbo - Oct 4, 2010 6:32 pm - Voted 10/10

Re: what about...

Depends on whether you know how old you are.

AlInTor - Sep 12, 2010 2:48 pm - Hasn't voted

climbing v. driving

"The statistics reveal that the real danger of a climbing trip is the drive to and from the climb."

You're implying that climbing is safer than driving. Psychologically, I like this conclusion. It can help me justify the activity to people who ask me "why the hell would you want to climb that? It's dangerous." However, the statistics you've put up state that if you get in an accident while climbing you are more likely to be injured and waaay more likely to die in comparison to being in a car accident. In terms of the frequency of car accidents and climbing accidents, as noted by others, there needs to be a meaningful way to compare the relative frequency of accidents between the two activities. It would be interesting to see, in an academic sense, the relative accident frequency rates of the activities and then factor in the higher injury and fatality rates of climbing. I wonder if the conclusion would be the same.

Unfortuantely...I don't know where you'd find the data and I don't know what purpose it would serve. I mean it could be an interesting academic discussion, but climbing is a dangerous activity. Is it more or less dangerous than X, Y or Z activity? That depends on what you're talking about. The relative danger certainly will not eliminate the very real existential danger of climbing.

BTW great website


StephAbegg - Sep 12, 2010 4:20 pm - Hasn't voted

Re: climbing v. driving

Assuming a factor of 50 (which is dubious as above arguments have mentioned, although I'm not sure if it should be increased or decreased, based on my personal climbing:driving ratio), then I believe this statement factors both the accident frequency rate plus the fatality rate of climbing:
"Taking the US population as a whole, a person is 1,500x (/50 = 30) more likely to die in a traffic accident than in a climbing accident."
So, a factor of 30 in favor of living longer if you climb...=)

chugach mtn boy

chugach mtn boy - Sep 13, 2010 6:15 pm - Hasn't voted

Re: climbing v. driving

Well, there are a lot of apples to oranges comparisons in the way you're looking at this.

Driving is very safe relative to serious mountaineering. Your risk of dying in a SINGLE attempt on Mt Everest (1.6%) is about three times your LIFETIME risk of dying while traveling in a car or pickup truck (0.5%).

Of course, for the general population, the risk of dying on Mt. Everest is something ridiculously small, like 0.000001%, whereas for the general population the risk of eventually dying in a car is ... 0.5%. But that doesn't mean it's safer to climb Mt Everest than to drive to grandma's house.

If you live in the US, though, driving your car to Mt. Everest probably IS more risky than the climb itself ...


triyoda - Sep 19, 2010 10:26 pm - Hasn't voted

Re: climbing v. driving

I think the obvious reason that climbing accidents have a higher incidence of death in the statistics is due to reporting bias. I think it is safe to assume that nearly all climbing accidents involving death are reported. An unknown (assumed large) proportion of minor accidents go unreported, whereas almost any auto injury is reported due to insurance/legal reasons.

I think the only conclusions that could be drawn is that the statistics suffer from too many unknown factors to make much in the way of useful inferences.


StephAbegg - Sep 13, 2010 1:44 am - Hasn't voted

Re: I find it...

Iowa would fall under the category "Central" which according to the pie charts has 2.3% of the mountaineering accidents and 1.1% of the mountaineering fatalities in the US. From the raw AAC data tables I used, this equates to 134 accidents and 17 fatalities between 1951-2006. At least one of these has had to occur in Iowa. Maybe....

(By the way, here's a link to the raw data for the 2007 Statistical tables I used off the AAC website.)


hellroaring - Sep 12, 2010 5:33 pm - Hasn't voted

Not so sure...

...interesting that there are no mountaineering accidents in Iowa.

actually i'm sure sometime/somewhere a climber that's been exiled to Iowa or Kansas has peeled off the top of a silo while fantasizing about sunbleached granite!...


mike_lindacher - Sep 12, 2010 9:44 pm - Hasn't voted

Rorschach Cartogram

I see a butterfly and / or a lobster ....


BobSmith - Sep 12, 2010 10:11 pm - Voted 10/10


The graph that surprises me the most is the experience level! It seems to be evenly divided.


StephAbegg - Sep 13, 2010 1:38 am - Hasn't voted

Re: Surprising!

On equal ground experienced climbers might be less likely to get into trouble than inexperienced climbers, but on the other hand they tend to attempt more challenging (and probably more dangerous) routes....

Viewing: 1-20 of 47