Half Dome Trail Visitor Use Monitoring Report

Half Dome – Yosemite Musing 

***LONG but important***     

     The Visitor Use & Social Sciences Branch of Yosemite has just released their exhaustive 42-page analysis called the Half Dome Trail Visitor Monitoring Report. You can read the entire text at


     For those that have other pursuits I’ll summarize the greatest hits.  From mid-June to mid-September, there was an extensive trail monitoring and human count (by humans of humans) on the Half Dome trail (after the split of the John Muir trail). This is 2-miles from Half Dome. Unseen to most were electronic counters called TRAFx that were mounted to trees that recorded the passage of warm bodies (deer? bear? Big Foot?) . In addition, a device called an Eco-Counter provided redundant counting and also recorded direction traveled. 21 photos a day (266 total) photographs were taken of the cables and summit. 

    Time and people flows were measured between 4 points: The JMT-HD trail split; the base of Sub Dome, the Saddle and the summit. The mean times to get up the cables was 29 minutes on permit days and 41 minutes on non–permit days.   In 2010, at total of 40,656 people actually went up and down the cables. (The number of big wall climbers who did not go up the cables but did come down was not measured.) This is way less than the 50,000-80,000 estimated from previous years. Permit days averaged 301 people per day; non-permit days it was 635. The park defined “free flow”condition as taking 23 minutes to go up and 19 minutes to go down. Two thresholds were gauged – the baseline was that 30 people on the cables at one time would yield an “unimpeded travel” experience on the cables and 70 people would yield a time when hikers would “percieve safety issues and unacceptable experiential conditions.” Their results showed that on permit days the 30 number was exceeded on 15% of the days and the 70 number never. However, on non-permit days, the 30 number was breached 65% of the time and the 70 number 23%. Also, the average cable loading on permit days was 305 even though 400 permits were available each day. “Unimpeded visitor travel” numbers are pretty subjective. This implies that if a person has to wait at all they may perceive it as a bad experience. Real world hikes show that if one person freezes up on the cables everyone below is impeded – regardless of the number on the cables. The study did not factor in hikers who simply should not be there and slowed everyone down. 

     An strange number in the tables showed that the max number recorded on permit days was 481 – how did that happen if 400 permits were given out?  Monday and Thursday both had a max of 872 – similar to the ”old days” on weekends. On the uncontrolled non-permit days the number averaged 635.   Bottom line – after much regression analysis, Mann-Whitney non-parametric tests,  the conclusion was that the old weekend load moved to weekdays and the permit system would be needed every day to maintain the safety and acceptable experiential levels. 

     A follow-up report to come out in January will address 4 “Visitor Use Management Scenarios.” The report did not say if this would guide what mangement would use for the 2011 Cables process.

1. Keeping a 400 person load with the existing permit system. (my comment: A permit system to spread the 11 am – 2 pm crowding could be alleviated with a Disneyland type am/pm window allowed. Hourly admittance times would permit more on the cables, spread out through the day

2. Determining the maximum number of people per day to maintain “free flow” conditions. (my comment: My free flow record time is 7.5 minutes upa nd 5.5 minutes down. It’s not clear how their numbers of 23 minutes up and 19 down were arrived at. Did that allow for photos? Allow for enjoying the view? What climbing technique was used? I face up and use one cable both up and down.

3. Lightning descent – Time estimates for panic summit evacuation in an emergency. (my comment:  Storms don’t instantly appear. A ranger decision halting access when threatening clouds present solves that.

4. Mandatory use of via ferrata – harness with dual cable/cabibeeners. (My comment: Practically of visitors spending $100+ for proper gear is doubtful. Training on use needed. Use would slow down ascent/descent radically and remove self assessment of risk/utility. Anticipate negative response from big wall climbers – now totally unregulated. NOTE: the word used is mandatory

Missing from report – 1) Engineering analysis of the structural integrity of the cable system and attachment points. It’s essentially 1919 technology with the latest cable replacement in 1984. 2) No mention is made of educating visitors. How many read the website information? With a target of 400 hikers per day, four 30-minute pre-hike encounters with a ranger discussing water, footwear, safety precautions, weather, etc. could be conducted during the day before a hike at the Valley Visitor Center auditorium. This could be replaced with a comprehensive video with a stand-by ranger/volunteer expanding and fielding questions. Upon completion, the visitor is given a “completed orientation” card that must be carried and shown to the subdome ranger for access with permit. Orientation need not be taken again that year. 

Finally – A nit – The report calls it “Nevada Falls – it’s singular – FALL. 

Unrelated thought worth quoting: “A determined person will do more with a pen and paper, than a lazy person will accomplish with a personal computer.” – Catherine Pulsifer

*MrHalfDome – Rick Deutsch – www.HikeHalfDome.com


3 Responses to “Half Dome Trail Visitor Use Monitoring Report”

  1. Mr. Diving Board Says:

    Next time, lead off with their incorrect identification of Falls versus Fall. It invalidates every other piece of data in the report. Question everything. I didn’t see mention of the gondola or zip line off the Visor, nor mention of the hot dog cart that got blown off the Dome next to the helipad.

  2. mrhalfdome Says:

    The Half Dome Snack bar has pretty good hot dogs. But there’s a line there also.

  3. john Says:

    Perhaps 2011 will bring the addition of Fast Pass, and early admittance to only those who stay at the Awahnee.

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