Recently, I revisited some old map and GIS files in search of the vector file I used to show the historic shoreline of the Bay Area…
in the News
As I took a closer look at the layers used compose such maps the N.C. Nelson Shellmounds Coastlines: Then vs. Now…. I realized the base map was actually a custom job.
I vaguely remembered having to do a lot of work in the beginning to make that shoreline map because I was just learning how to use GIS software. But I didn’t remember the specifics. And, I couldn’t find an original file for the project that wasn’t already incorporated into a larger project.
So, I did what I probably should have done in the first place, and took a look at the data table, to find some identifier that Google would help me resolve. That identifier came as a “Project ID” number: “CA37B01”.
I found the “CA37B01” dataset referenced in a NOAA Shoreline Data Rescue Project data dump,
Even better: the website took me to another place where I could search for and download the files I wanted, The National Geodetic Survey – NOAA Shoreline Data Explorer… Which is better than the regular National Shoreline Data Explorer, because it loads faster, and is easier to filter. Also, the difference between vector and raster files is very clearly delineated.
Once I got everything mended together, I had a redux of the “Pre-1900 Historic Shoreline of the San Francisco Bay Region”.
THIS MAP NO LONGER EXISTS (Sorry)
Please use the Historic Shoreline of the San Francisco Bay Area Map for reference, instead.
As awesome and fun as this is, the map is still missing Goat Island–known as Yerba Buena Island Today–which Treasure Island was built (or filled) next to, and the San Francisco Bay Bridge was built (tunneled) through. Mapping of Goat Island does not appear to have occurred until after the year 1900. I could not find any T-Sheets or National Shoreline Datum in either vector or raster form showing Goat Island.
It’s a little disappointing. But it does not invalidate or really detract from the overall purpose of this project; which was to show the Pre-1900 Shoreline of the San Francisco Bay Area.
Update: October 2025
After revisiting the original shoreline data, I expanded this work into a full interactive map covering the entire San Francisco Bay Area. The new project, titled Historic Shoreline of the San Francisco Bay Area, combines all of the pre-1900 shoreline and wetland data into a single handmade, open-access map.
This is the first time the entire Bay’s historic coastline has been reconstructed and shared publicly in an interactive format. It connects the dots between earlier projects like the Alameda Shellmound Map and the Nelson-Duncan Shellmound Survey, revealing how much of the Bay’s edge has been altered or erased over time.