“The Half Dome Cables Study” Part 3

Half Dome – Yosemite Musing

As we analyze the 20008 RSG study on the Half Dome cables, we learn now that in addition to the raw body count of people going up the cables, the team also gave time stamped cards to parties going up the trail. They got over an 80% “cooperative” participation. Surveyors were stationed at the subdome, base of the cables route, and top of the cables route. Then the survey took an interesting twist: they asked the people if they had traveled outside the cables on ascent or descent of the cables route, and if so, to select from a list of reasons on the survey card or give a different reason that best explained why they did. It seems to me that from here on the focus was not so much on the crowding on the cables, but on the outside climbers. More on that later. The next thing they did was to set up a camera that snapped shots of the cables every 20 minutes for 16 days. The camera was on the top of sub dome. The study estimated that it captured 95% of the cable route. Somebody then looked at the hundreds of photos and marked each human with a dot – yellow if waiting, green if hiking up between the cables, red if outside the cables. The photos below show this.  Your browser  my allow you to click to enlarge them.

Raw photo

Zoomed in portion

Next , a verbal interview was conducted with hikers on sub dome. Anyone in the audience participate? The survey was to explore visitors’ perceptions of risk, safety, crowding, and acceptability of management actions, all with respect to the Half Dome cables route. Thus, survey results were intended to support NPS management decisions designed to address visitor safety and crowding issues on the Half Dome cables route. That last sentence came right out of the report. Read it again. I’ll leave interpretation up to you. 291 completed the survey – so less than 300 of the estimated 50,000 Half Dome hikers were key to determining the permit system. A couple more interesting facts. The number of people in a group surprised me. 12% are solo hikers, 44% are a twosome, 18% are in threes and 12% are foursomes. Parties of 5 or more are rare. Finally, one last bar chart. This one shows the number of people arriving at the Half Dome – JMT trail split. Gee, Sunday and Friday are about the same as any other day of the week. Hmmm

The light boxes are just those who went on to the cables.

Unrelated thought worth quoting: “God has cared for these trees, saved them from drought, disease, avalanches, and a thousand tempests and floods. But he cannot save them from fools.” – John Muir

*Mr. Half Dome – Rick Deutsch –  www.HikeHalfDome.com


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