I made a poster of climbing routes on Rainier. Below is a reduced sized version. The full-resolution image of this poster for printing is available in my online store.

Query page: http://www.mountrainierclimbing.us/routes/stats/routetotals.php
NPS website: http://www.nps.gov/mora/parkmgmt/index.htm

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.)

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.

Query page: http://www.mountrainierclimbing.us/weather/weather.html

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.

Query page: http://www.mountrainierclimbing.us/sar/sarlist.php

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.

Query page: http://www.mountrainierclimbing.us/sar/fatalities.php

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.

Query page: http://www.mountrainierclimbing.us/routes/stats/routetotals.php

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 go to 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.

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 likelihood 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 disproportionately skewed towards out-of-state climbers (reference).

Data: http://www.nps.gov/mora/planyourvisit/annual-mountaineering-reports.htm

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.

I also have a separate statistical study on mountaineering accident data, based on the yearly AAC accident tables.