Mount Diablo Surveyors Historical Society
Initial Point Celebration
The Mount Diablo Initial Point Plaque
Mount Diablo State Park, Contra Costa
Mark Lewis, P.L.S.
the opportunity to attend the Mount Diablo Initial Point plaque installation
celebration last weekend. There was a barbeque in Mount Diablo State Park
with a raffle in the morning and a tour of the museum with the new plaque in
the afternoon. I sure had a good time.
To make a long story
short, the reason for the new plaque is this: In 1851 Col. Leander Ransom
established the Mount Diablo Initial point, for the surveying of the public
lands. His monument was a small depression in the highest rock atop the
mountain. Then in 1852 R.D. Cutts of the U.S. Coast & Geodetic Survey
needed a good spot for a control point so he set a brass cap 3 feet Southeast
of Ransom's initial point.
Mount Diablo State Park
was dedicated back in 1921, and again in 1931. At some point in time, the
visitor's center was built at the top of the mountain around both of these
monuments. Unfortunately, a plaque was installed that incorrectly describes
how the USC&GS monument (which someone has removed and only the bolt is remaining)
is the initial point for the Mount Diablo Baseline & Meridian.
This didn't settle well
with my friend John Pettley back in 1985. Well, it's been 8 years, lots of
pushing from members of the No. Calif. section of ACSM, East Bay, San
Mateo/Santa Clara, and Monterey Chapters of CLSA, some string pulling from
Bud Uzes of the State Lands, an AutoCAD drawing from hell, and 3 boxes of
paperwork to remove the old plaque and install a new one which reads as
WITH ITS UNOBSTRUCTED VIEW, MOUNT DIABLO'S SUMMIT
HAS LONG BEEN AN IMPORTANT REFERENCE POINT FOR LAND SURVEYS IN THE FAR WEST.
IN 1851, COL. LEANDER RANSOM BEGAN SUBDIVIDING THE PUBLIC LANDS BY
ESTABLISHING THE MOUNT DIABLO INITIAL POINT. FROM THIS POINT, LINES WERE
EXTENDED NORTH, SOUTH, EAST AND WEST FORMING A SURVEY GRID THAT COVERS MOST
OF NORTHERN CALIFORNIA AND ALL OF NEVADA. THIS POINT IS MARKED BY A
RECTANGULAR DEPRESSION IN THE EXPOSED BEDROCK, THREE FEET NORTHEAST FROM THE
CENTER OF THIS PILLAR. IN 1852, R. D. CUTTS OF THE COAST SURVEY ESTABLISHED A
DIFFERENT SURVEY MARK FROM WHICH HE BEGAN MAPPING THE STATE'S WATERWAYS AND
SURROUNDING TOPOGRAPHY. THIS POINT IS MARKED BY THE COPPER BOLT INSIDE THE
BASE OF THIS PILLAR.
Inside the museum
is an old transit and grunters chain from the late Cecil Hansen's collection
donated by his son, and an old field book donated by Bud Uzes.
The installation celebration took
place on July 17,1993 and was the 143rd anniversary of Col. Ransom's survey.
It was a great summer day in which I had the pleasure of seeing some old
friends and meeting some new ones.
Thanks and congratulations to John Pettley, Steve Wilson,
Myron Lewis, Mount Diablo Surveyor's Historical Society and everyone else who
made it happen.
Reprinted from the Fall 1993 Issue, # 102 of the California
Surveyor “Letters To The Editor” section with edits by Michael J. Foley, PLS,
all rights reserved.
To read the full text of the plaque, click here. To see
a photo of John Pettley with the plaque and its
location on the piller
to Articles Index page
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