Home | Mount Diablo Surveyors Historical Society

Welcome to Mount Diablo Surveyor Historical Society

The Society membership is committed to preserving the artifacts and records of land surveyors who have worked in and around or have been influenced by the Mount Diablo Meridian located in Contra Costa County in Northern California. Various photos (by drone) have been provided courtesy of California State Parks.

California's Initial Points

California has three initial points; Mount Diablo Base and Meridian (est. 1851) (center), San Bernardino Base and Meridian (est. 1852) (bottom), and Humboldt Base and Meridian (est. 1853) (top). Initial points are the starting points, and were established to describe and enable the government to sell public lands covering California and Nevada which were part of the Public Lands Survey System (PLSS).

Mount Diablo Initial Point

San Bernardino Initial Point

Humboldt Initial Point

Membership

The Mount Diablo Surveyors Historical Society (MDSHS) was created to enrich the general public by collecting, preserving and displaying the knowledge, technology and artifacts of the land surveying profession. The Society is a nonprofit public benefit tax-exempt corporation, and any donations of monies, grants or artifacts are fully tax deductible.

To become a member, please fill out this form and mail it back to us.

175th anniversary of the Initial Point

Join us at Mount Diablo to celebrate the 175th anniversary of the Initial Point.

Download Flier here

Next Meeting! June 1, 2026 (6:00 pm)

Sat, 05/23/2026 - 12:20pm by KeithN

We currently have regular meetings on Zoom.
Please send us an email (mdshsorg@yahoo.com) requesting Zoom access information if interested in attending a meeting.