Alameda County High Point Trip Report
Date: June 2002
California's Alameda County High Point is Discovery Peak.
"County High Points" by Andy Martin lists two summits as possible high points of California's Alameda County:
(1) an unnamed point, referred to by Gary Suttle in his "California County Summits" as "Discovery Peak"
(3,840+ feet) and (2) point 3841 about 1.5 miles to the southeast. Recently, Edward Earl and Bob
Packard independently climbed both points and noted that an unusual 10 foot boulder was the high point of
the southeast summit. Both Edward and Bob again independently judged (by purely visual means) the two
contending summits to be so close in elevation that they urged that both peaks be climbed in order to be
assured that the high point of Alameda County was indeed climbed. Adam Helman confirmed Edward's opinion
(again, by purely visual means) at the very time they had climbed the two highpoints together.
So, when Barbara Lilley and I subsequently climbed "Discovery Peak", we were completely resigned to need
of visiting the southeast peak also. Upon arriving at "Discovery Peak", it sure appeared, visually anyway,
that the southeast peak was definitely in contention. However, prudence suggested that, before finally
committing to hike those additional four round-trip miles to that southeast summit, I should use my 9"
NIKON surveyor's hand level to see whether it could resolve the issue. Sitting down on a rock outcropping
at the local high point, I found a comfortable position upon which to brace my arm against the rocks in order
to minimize jitter effects while sighting the hand level. I was surprised to see that the hand level's horizontal
cross hair of the leveling mechanism was bisecting the distance trees on the southeast summit near their
crowns. WOW !!! This surprising result invited further investigation.
First, I needed to confirm that I was indeed looking TOWARDS the high point. For this purpose I used a
GARMIN GPS III PLUS to provide the bearing to the southwest summit. I had previously set a way-point
at the high point of the southwest peak using the DELORME 3-D TopoQuads program. The highest
magnification level (equivalent to viewing the topo at a scale of 1:6.400) had been employed, and the high
point had been determined by carefully moving the cursor within the highest closed contour). Now, using a
SILVA Ranger precision compass and setting the bearing at that indicated by the GPS, I confirmed that I
was indeed looking at a row of the highest visible trees along the line of sight to the high point.
The uncertainty of the line of line of sight should be within about 1 degree of azimuth - roughly equivalent
to about 100 feet perpendicular to the line of sight (at the distance of the southeast summit).
Before leaving home I had used the DELORME TopoQuads program to print a topo map of the planned
hiking route between the two high points, and this showed that the ridge on which the southeast summit lay
was approximately perpendicular to the line of sight. This meant that the highest trees would also appear to
be aligned perpendicular to the line of sight, as would also the ground/bush surface along the top of the ridge.
Therefore, I used a R.E.I 8x power monocular to examine the trees themselves and also the terrain at
the foot of the trees on either side of the line of sight towards the summit. First of all, all of the observed
trees appeared to be mature pines, unlike the majority of the trees near "Discovery Peak" which were oaks.
Also, individual trees could be resolved at a certain height above the apparent ground/bush level. The
ground/bush level could be visualized, because the sky could be seen peaking through at five or so places
spaced out along the tree front. The cross hair of the leveled NIKON instrument intersected the tree tops
approximately 2/3 of the height above the apparent ground/bush surface. Observed this way, it means that
the bush height is relatively unimportant, because as a little algebra shows:
Height of the leveled line of sight above ground level = h +(2/3)*(H - h) = (2/3)*H +(1/3)*h,
Author: Gordon MacLeod
where H is the height of the trees and h is the height of the brushes.
Note, in particular, that the "h" or brush height term is additive. So, a conservative estimate of the height of
"Discovery Peak" above the southeast summit would be just (2/3)*H.
So, just how high are those pine trees? Suttle mentions only the Digger Pine as being present in his Alameda
County Summit's environmental description, although he does mention that Knobcone and Coulter Pines -
as well as Digger Pines -- are present at Mt. Diablo -- some miles to the north. In "Trees of North
America", C. Frank Brockman gives the range of heights for Digger Pine as 40 - 60 feet, for the Knobcone
as 40 - 75 feet, and for Coulter Pines as 40 -80 feet. Using the lowest height (40 feet) for all three of these
pine in order to determine a conservative estimate:
Height of "Discovery Peak" above the southeast summit is at least = (2/3)*H = (2/3)*40 = 27 feet.
Gee, 27 feet! So a comfortable margin exits with which to accommodate a 10 foot boulder -- no matter
how cute. Too bad I couldn't see the boulder from "Discovery Peak" for it would have spared all this
Incidentally, my analysis using the DeLorme TopoQuads program of the relative heights of "Discovery Peak"
verses its southwest competitor shows that the "Discovery Peak" is higher by the same 27 feet -
probably an incredible coincidence. This analysis goes beyond just moving a cursor looking for the highest
point within the encompassing contours of both summits -- although that process also yields the same 27-foot
advantage for "Discovery Peak" in this case.
So, all of you who have merely only climbed "Discovery Peak" can now sleep better at night knowing that at
least one analysis has shown that slothfulness pays, and for those contemplating climbing the high point of
Alameda Country can be more confident that "Discovery Peak" is IT. And for those who have climbed both summits,
you already know that you cannot lose.