One morning I woke up wondering how many people climb Mt. Rainier each year. I got kind of carried away, and two days and several colorful pie charts and graphs later, I decided I had answered my question sufficiently. The result was the following statistical study.....

Mt. Rainier Climbing and Accident Data

  Total Annual Climbers over the last Century • Summit Success Rates and Number of Climbers by Month, Weekday, Party Size, and RouteTemperatures and Wind Speeds at Camp MuirSearch-and-Rescue Data and CostsAccident CausesTotal Fatalities and Annual Fatality RatesClimbers by Home State • Guiding Services Breakdown

The National Park Service continually collects statistical data pertaining to climbing Mt. Rainier. This data is presented on their website in query tables. In looking for a way to fulfill my incessant need to play around with statistical data, I scrounged as much data as I could from the query tables, and used it to create the colorful graphical display of pie charts and graphs on this page. I've left most of the statistical interpretation/conclusions up to the viewer, so just browse around and look at whatever statistics pique your interest.

Website I used for most data:

Important Note: I did this study in February 2011, so I used the data available at that time. The NPS website has plans to add more data resources in the future.

How many climbers attempt Rainier every year? How has the number increased over the last century? What is the success rate, and has this changed over the last half-century? 1852-1897, 1950-2009 NPS data.

Summit Success Rates and Number of Climbers by Month, Weekday, Party Size, and Route, 2002-2010, 1950-2009

Query page:
NPS website:

A simple Google search of "Rainier Statistics" produced a table from the NPS website summarizing the yearly total climbing parties and successful summits going back as far as 1950. This is the plot shown above, which shows how dramatically the number of climbers (but not really the success rate) on Rainier has increased over the last half-century.

Since 2002, Mt. Rainier National Park has kept records of climbing parties (for registered parties at least, which is a requirement that is enforced pretty heavily in the park.) Up until 2006, guided parties—which account for about 4000 climbers/year—were not included in the total.  Since 2006, though, the public records include guided parties and hence give a more accurate representation of the number of climbers on various routes on Rainier. On the query page, the records are separated by Route, and contain variables such as Date, Party Size, and whether the party successfully made it to the summit. There were a lot of plotting options for this data. Below I show some plots of how the number of climbers and success rate varies over the course of the year for different routes.
(Below I only give individual plots for four popular routes, although I could easily make a chart for each route - email me if you want to see a different route.)

I recently made a poster of routes on Rainier, which is given below as well.

Summit attempts and success rates by month. Most popular summer route.
2006-2010 data. day instead of month.
Summit attempts and success rates by month. Popular summer route.
2006-2010 data.
Summit attempts and success rates by month. Typically climbed early in the summer.
2006-2010 data. day instead of month.
Summit attempts and success rates by month. I thought this was a good example of a clearly Spring route where poor weather and conditions limit the success rate.
2006-2010 data.
Climbing Seasons by Route: Assuming that climbers have an accurate sense of what seasonal conditions are most likely to get them to the summit, the route success rate curves should represent the "best" climbing seasons for their respective routes. Note that this assumes that the skill level of the climbers on the route is not skewed throughout the year; however, it is likely that climbers attempting a route out-of-season are on average more likely to get to the summit than the average climber on that route, so assuming a consistent skill level throughout the year will cause the "route climbing seasons" to be a bit wider than they should be for the average climber.
Which routes are climbed earlier/later in the season? How many more people climb Disappointment Cleaver than Emmons Glacier? Are the successful climb distributions similar to the total climber distributions? (shown as both total number of climbers and total number of successes for each month)
2006-2010 data.

How does the number of successes vary on a route throughout the year? Which routes are the best bet for an early season attempt? (calculated by dividing total monthly successes on the route by total annual successes on the route, so area under each curve is equivalent, regardless of actual popularity of route)
2006-2010 data.
Which routes have the most climbing parties per year? Which routes have the highest success rates?
(Note that routes that are rarely climbed might have anomalously high or low success rates—for example, if a route is climbed only once in a year, it will either have a 0% or 100% success rate depending on the luck and skill of the climbing party.)
2006-2010 data.

Poster of Climbing Routes on Mt. Rainier, by Steph Abegg.
Not considering route, what are the most popular seasons for climbing Mt. Rainier? How does the summit success rate vary with season?
2006-2010 data.

Not considering route, what are the most popular seasons for climbing Mt. Rainier? How does the summit success rate vary with season?
This is the same data as for the chart to the left, but plotted by day instead of month.
2006-2010 data.

Is Rainier climbed more often on the weekends than weekdays? How does the summit success rate vary with day?
2006-2010 data.

Not considering route, what is the distribution of party sizes Mt. Rainier? Overall, do smaller or larger parties have a higher summit success rate? Note that since more difficult routes are attempted by smaller parties, the success rate for smaller parties is smaller. See below for analysis of just one route.
2006-2010 data.

Interesting comparison: Distribution of party sizes on the Disappointment Cleaver route, which is the route used by 64% of climbers on Rainier:
...Party sizes on DC Route only.

Temperatures and Wind Speeds at Camp Muir

Query page:

There are various weather-monitoring stations in Mt. Rainier National Park. One is at Camp Muir at elevation 10,080' on the popular Disappointment Cleaver Route. The plot below shows the average daily and monthly temperatures and wind speeds throughout the year.

Average daily and monthly TEMPERATURES and WIND SPEEDS at Camp Muir.

Search-and-Rescue (SAR) Data, 2010

Query page:

When I did my statistical study, the only search-and-rescue data on the website was for 2010. This data consisted of 42 search-and-rescue events in Mt. Rainier National Park over the course of 2010. Variables included Activity, Cause, Primary Injury, Duration, Notification Type, Age, and Sex. The cost of each SAR event was also recorded. Pie charts were my plotting method of choice, and are provided below.

General Search-and-Rescue Stats

TYPE of SAR event.
Rescue, Search, Search & Rescue
ACTIVITY that led to need for SAR.
Climbing, Hiking, Skiing, Camping, Driving, Work
CAUSE of accident.
Fall, Altitude, Exhaustion, Medical Condition, Weather, Avalanche, Crevasse, Drowning
Primary INJURY.
Torso, Head, Medical, Environmental, Arm, Leg, Altitude, Hypothermia, Exhaustion, None
DURATION of SAR event.
<1 h, 1-3 h, 3-6 h, 6-12 h, 12-24 h, >24 h
Cell, Landline, Ranger, Radio, Public, Overdue
AGE of those involved.
by decade

SEX of those involved.
Male, female, multiple

Cost of Search-and-Rescue
(total of $189,244 for 42 Search-and-Rescues in 2010)

Which Activity (e.g. Climbing, Skiing, Hiking, etc.) leads to the highest annual Searchand-Rescue costs?
Which Activities (e.g. Climbing, Skiing, Hiking, etc.) typically lead to the higher Search-and-Rescue costs (for an individual event)?
Which Causes (e.g. Avalanche, Crevasse, Exhaustion, etc.) typically lead to the higher Search-and-Rescue costs (for an individual event)?
Which Injuries (e.g. Leg, Head, Hypothermia, etc.) typically lead to the higher Search-and-Rescue costs (for an individual event)?
Is the means of notification (i.e. Radio, Cell phone, Overdue) related to the Search-and-Rescue costs?

Fatality Data, 1897-2010

Query page:

Mt. Rainier National Park has kept detailed records of the fatalities within the park since 1897. Through 2010, there have been 378 recorded fatalities, an average of 3.3/year (note that this number says nothing about the per climber fatality rate, which is shown on the rightmost plot below). The fatality records include variables such as Date, Activity, Factor, Cause, and Location. Due to the increasing number of climbers on Rainier over the last century, the entire century of data (from 1897-2010) is not representative of the last couple of decades. Since 1897, the per climber fatality rate has declined drastically and the types of contributing factors and activities have shifted in importance. This is exhibited in the charts and graphs below.

Fatalities by ACTIVITY.
Climbing, Flying, Driving, Hiking, Skiing, Snowshoeing, etc.
Left: 1897-2010.
Right: 1991-2010.
Climbing Fatalities by FACTOR.
Fall, Avalanche, Rockfall, Exposure, etc. The data shown in these plots is just for the climbing-related fatalities in Mt. Rainier National Park (Activity="Climbing (Summit)").
Left: 1897-2010.
Right: 1991-2010 (quite different).

What MONTHS of the year have the highest number of Fatalities? How does the Climber Fatality Rate vary over the year, based on the number of climbers on the mountain? Plotted by 1950-1990, 1991-2010.
Which CLIMBING ROUTES have had the greatest number of fatalities? Which routes are the most dangerous? (Note that some locations are ambiguous or could be on multiple routes.) 1897-2010 Data.
Fatalities PER YEAR and PER DECADE and PER 10,000 CLIMBERS. 1897-2010 Data.

Climbers by Home State, 2010

Query page:

The climbing party data also included zip code of the climbing party leader. This data was pretty incomplete up until 2010. Since I lack good GIS software to plot the locations of the zip codes, I ignored this data. A fellow climbing-GIS enthusiast Michael Wilburn (at the University of Oregon) saw the gap in my analysis and filled it with the following map showing the distribution of how far and wide Americans come to climb Mt. Rainier. It's a really nice map.

And then I decided to make a cartogram (click here to open my cartogram page) whose distortions represent the relative fractions of state populations that climb Rainier.....The distortions on the cartogram are representative of the fraction of Rainier climbers in each state. Note that it would be incorrect to create a cartogram using just the total numbers of climbers from each state, as this would not consider state populations (for example, clearly 4 climbers from Wyoming would represent a much larger fraction of the population than 4 climbers from New York). To account for the sizes of the states, I normalized by population density instead of just population.

What are the home STATES of climbers on Rainier? Is the mountain mostly climbed by people in the Seattle area?
2010 data, made by Michael Wilburn.

Which states have the highest population fractions of Rainer climbers? Is Rainier primarily climbed by people from the West coast?
2010 data.

Is there any correlation between success rate and home state?
Do climbers from Washington have a higher summit success rate than out-of-state climbers?

Total Climbers Made it to summit Success Rate
ALL parties that provided ZIP code for a US state, 2010 data 8969 4179 46.6%
Parties from WA 7126 3387 47.5%
Parties not from WA
(= ALL - WA)
1843 792 43.0%
Parties not from WA or neighboring states
(= ALL - (WA+OR+ID))
1543 651 42.2%
Parties not from "The West"
870 315 36.2%

Conclusion: The summit success rate is highest (47.5%) for climbers from Washington, and in general the success rate drops as the residence of the climbing party moves further from Mt. Rainier (36.2% for climbers not from "The West"). This likely has at least something to do with the fact that climbers coming from further away have less flexibility to change their planned climbing date (pre-purchased plane tickets, for example), and hence have greater liklihood of climbing Rainier in less-than-ideal conditions than climbers from Washington who might be able to adjust trip dates more readily. Related to this tendency of out-of-state climbers to climb Rainier in less-than-ideal conditions is the morose statistic that climbing fatalities are disproportionatly skewed towards out-of-state climbers (reference). 

Guiding Services Breakdown, 2010


There are three commercial guiding outfits that are allowed to operate within Mt. Rainier National Park: Rainier Mountaineering, Inc., Alpine Ascents International, and International Mountain Guides. Of the approximately 10,620 summit attempts made in 2010, about 43% of them were made with one of these three guiding companies.

Although only 2009 and 2010 data were provided on the NPS site at the time of this analysis, the 2009 and 2010 data were nearly identical in their independent vs. guided and guiding services breakdown. The plot below is for 2010 data only.

Since I posted this plot, I’ve gotten a lot of questions about whether there is data that shows the success rate of the guided parties vs. the success rate of independents. However, the NPS data that I found only gives the total number of annual successful summits; I could not find any data that indicated how many of the parties that made it to the summit were guided and how many were not. Perhaps the fact that guiding services are not actively putting out this data suggests that the guided parties really don’t have much better (if at all) success rates than the independents.....but then you've got to also consider that guided parties on average represent less experienced climbers which would negatively influence the guided success rate.

What percentage of Rainier climbers are GUIDED? Which guiding service is the most popular?
2010 NPS data.