I currently have columns running in 3 newspapers;
- Tri-Valley Herald : Looking Back
- Valley Times : Do You Remember?
- The Independent : Do You Remember?
The Articles appear in the Herald and Independent on Thursdays,
and the Times on Sundays.
They will also be found on this page each week as well.
If you've missed any please follow the links on the dates to catch up.
Historic benchmarks along the road
By Barry Schrader.................................February
How many times have you been atop Mt. Diablo and never saw the geodetic
marker? Thats the brass disk embedded in cement inside the stone building.
This disk was placed there in 1852 by surveyors from the US Coast &
Geodetic Survey, only two years after our statehood. And that was a long
time before the building was located on that spot.
The significance of this survey marker, known as a benchmark, is that
all of Northern California was mapped using this as the land control point
which determined the borders of all townships, sections and even private
property lines. The location gave a straight line view all the way to Mt.
Lassen and Mt. Hamilton on a clear day.
Ken Lamb, now retired, but at one time the City of Pleasantons
surveyor and traffic engineer among other things, has spotted dozens of
these small brass or iron disks, about three-and-a-half inches across, while
doing surveying or just driving through the countryside. He recalls one
on top of Crane Ridge and others along the Pleasanton Ridge. After leaving
the city job he formed Lamb Land Survey and spent years spotting more markers,
some more difficult to locate than others. Since most of them were installed
50 to 150 years ago, geography has changed, roadways have been built or
widened, railroad tracks moved or torn up, and structures built where the
markers used to be set in concrete a little above ground level.
I then learned from my Heritage Estates neighbor Steve Gawura that the
Power Squadron, an organization of sail and power boat enthusiasts, had
adopted a nationwide project of locating and reporting all the remaining
benchmarks in the country that can be found. In the last 20 years Steve
himself has tracked down hundreds of these little brass disks (they were
made of iron during World War II though) and even a few months ago did some
sleuthing around the East side of Livermore. He adds that many water towers,
church spires and other tall structures have also been used by the Geodetic
Survey as reference points. Each benchmark disk is given a Permanent Identification
Number (PIN) stamped on its surface or painted on the cement in which it
is imbedded as well as the date of its original placement.
With his GPS unit (Global Positioning System) it was easy to find two
on Greenville Road. The most evident one along the roadway is on the west
side of Greenville across from Lupin Way as you enter the LLNL East Gate.
Near the roadway you can see a metal post and right next to it embedded
in a cement base is an iron disk (placed during WW II in 1944). Get up close
to read the sign on the stake and you will find it says Witness Post
which is the name of those remaining stakes that help pinpoint the location
of the ground-level markers. North of there on the same side of the road,
across from Old Patterson Pass Road, you will find a second one. But the
Witness Post has been bent over by an accident at some point.
The one in the Amador-Livermore Valley probably the most frequently
passed by unaware motorists is on Stanley Boulevard. I know I have driven
that road hundreds of times and never paid any attention to two concrete
pillars about three feet high next to the westbound lane. If you check your
car odometer, it is exactly one mile west of the traffic signal at Stanley
and Isabel. You will see the initials BM and a number painted
in white on the one pillar and if you can safely pull off the road there
you will find the benchmark embedded on top of the cement block, dated 1947.
If you are not satisfied locating just a couple of these, then go to
the website at www.ngs.noaa.gov/cgi-bin/ds_radius.prl and you can find the
locations of hundreds, maybe thousands more. At the latest count in December
2005 there were 736, 425 spread throughout the US. And if you really like
a challenge, climb Half Dome and find the one there. I learned of its existence
while in the cocktail lounge at Yosemite Lodge a year ago. Used as decorations
in the top of the bar were benchmark disk replicas from around the Park.
I found you can also buy them for $39 in the gift shop next door.
Steve related one of the most unique experiences he had years ago while
tracking the elusive little disks in Durango, Colorado. Their team zeroed
in on a marker that was supposed to be on the side of a schoolhouse in town.
They found the coordinates and it appeared the brass disk was buried under
a dozen layers of paint on the wall about four feet above ground. As they
struggled to chip off the layers the school janitor confronted them to demand
to know what they were doing to the side of his building. As they were trying
to explain the significance of this historic marker the school
principal arrived on the scene to investigate the matter. After they gave
her the full explanation she was thrilled to know they had found such an
historic piece of Americana on her building that her students could learn
Now heres a history mystery for Sandia National Lab employees
to solve. According to federal records there is a benchmark disk on their
site somewhere 25 feet west of Avenue A on the concrete surrounding a manhole
cover. The GPS coordinates are North 37 degrees, 40 minutes, 48 seconds,
and West 121 degrees, 42 minutes, 21 seconds. Will someone there be able
to find it or is it long gone? It was installed in 1957, just a year after
Sandia was founded in March 1956 (which happens to be 50 years ago this
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PO Box 446
Livermore, CA. 94551