Marin County Highpoint Trip Report
Mount Tamalpais (West Peak - 2,576 feet)
Date: Apr. 19, 2016
Author: Greg Slayden
I recently changed the Peakbagger.com listings for the summits of
Mount Tamalpais so that the West Peak is now the Marin County high
point and 2000-foot prominence peak, and the East Peak (tourist summit)
is now just a sub-peak.
As part of this change, I have "grandfathered" in all current CA CoHP
list completers who had not yet logged a West Peak ascent. I did this
by creating a new kind of ascent, a "grandfather" ascent that is
normally hidden except for list completion purposes. So the FRL and
automated completion maps for current CA completers remain the same.
Once a completer visits the West Peak, the "grandfather" ascent is
then removed.
Incidentally, this research was initiated by the periodic review
that is done to match up the peak databases of ListsOfJohn and
Peakbagger so that the mobile app can log ascents at both sites
at the same time. ListsOfJohn has always had the West Peak as the
highest, although I suspect that quite a few people on LOJ have
logged the West Peak as a CoHP thinking it was the East Peak.
As someone who now sees my CoHP and P2K counts drop by one, I feel
the pain of those in the same boat. There is nothing I would like
more for a conclusive survey to show that the much more attractive
East Peak that I climbed long ago is higher.
But for me, I cannot ignore the principal evidence of the Marin
County government's online GIS map. I have seen many of these maps
from county planning/GIS departments, and there is a rough correlation
between the affluence of the county and the quality of the mapping
site. Marin is one of the wealthiest counties in the USA and their
map is absolutely first rate. The difference of 4+ feet between the
summits on that map is actually quite a bit, since I can think of
other situations where a peak is awarded high point or prominence
status by only 1 or 2 feet.
I normally don't trust handheld GPS readings too much, but Bob Burd's
results are at least consistent with the map. I welcome any and all
feedback from people in the area with sight levels, differential or
handheld GPS, or other surveying equipment.
Reports are that if one hikes the fenceline around the West Peak
military compound, one's head is above all of the man-made levelled
platform inside the fence. This would appear to constitute an ascent
under the "rules", I would hope. So hopefully this "new" high point
is at least accessible.