[pct-l] Data Book Discrepancies

[Barry Teschlog]

Jalan Wrote:

I have seen other discrepancies as well  (data book, WP guide, half mile. Blacks guides, etcc )it would be nice to have an agreed upon standard but judging by recent posts , there is some rancor around this subject I've always been annoyed that the WP guides always refer to distance between points rather than overall mileage points but I guess that makes the data less susceptible to overall changes on the trail length re routes etc It seems like the PCTA should set the gold standard. If they have apparently the word has not gotten out

Reply:

In regards to ANY person's distances, no matter the source, I'd suggest 
its not so simple.  Even if everyone was on the same page as to exactly 
what the route is, everyone, when they walk it, is going to come up with slightly different distances depending on the equipment and methods 
used (and even the conditions under which the measurements are made - 
http://en.wikipedia.org/wiki/Error_analysis_for_the_Global_Positioning_System).  Add to that, there are some parts of the "trail", or the route, that 
really beg the question as to how to measure them.

A concrete example of this latter point that I'm very familiar with is 
between the southbound trail head and the northbound trail head at 
Snoqualmie Pass.  A quick Google Map of the route one would likely walk 
from trail tread at the southbound TH to (main thread) trail tread 
coming from the NB trail head indicates the distance is about 0.59 miles (and even that number has false precision associated with it).  OK, so 
is this included?  Where's the break point between Section I and Section J?  Which user (day / section or thru) is being measured for, since a 
section or day hiker isn't going to start under the I-90 bridge and go 
up the side trail northbound, or walk to the SOBO TH, but will drive to 
and leave from either trail head parking lot.  Note that I used the side trail access to the NB trail on the above estimate - even that is open for "debate" - is the right way to walk around on the road via the parking lot?  This is but one example, one I happen to know of 
specifically.  Multiply that by how many times up and down the trail, 
combined with the perpetual changes to the trail from year to year and 
it can be seen that of course distances are going to vary from source to source.  Which is right?  Shrugs, since it really doesn't matter, IMO.


In the grand scheme of things, the above 0.59 miles, give or take, is "in 
the noise" as an engineer would say.  Arguing about tenths of miles, or 
even single digit miles, over the length of a 2,660 mile trail (give or 
take) kind of misses the inherent accuracy and precision of the 
measurement.  


After all, I say that 2,663 Angels can fit on the head of a pin and that 
other person who says that 2,662 or 2,665 can fit is so blatantly wrong that their 
motives must be pure evil and they're the spawn of Satan for even 
suggesting it.  Tongue firmly in cheek on that last part.


YMMV (literally), HYOH, 2 cents, first to Canada loses, yadda, yadda, yadda

Barry

PS
 - The snow is melting here in the great Pacific Northwest.  If you're 
interested in taking care of the PCT here, we have a work party at 
Stevens Pass June 28-29 and will start logging out south of Snoqualmie 
Pass probably the 4th of July weekend.  Our 3 day work party Aug 22-24 
needs more people as well.