December, 2022

In the late 1800's, the East Oakland Street Railway constructed an electric streetcar to bring people to an area outside of Oakland then known as Indian Gulch. At the end of the line, the tracks extended across a wooden trestle and left visitors at a stop in the hills above Lake Merritt. The line only lasted a few years, and by 1905 or 1906, the trestle was torn down to prepare for the construction of houses in the newly named neighborhood of Trestle Glen. There are several theories as to where the trestle was actually located, but so far there has been no conclusive proof. Different maps of the time show the route in slightly different locations, and because the landscape was significantly changed when houses were built, it is difficult to use photographs to pinpoint the exact location.

Since we moved to the neighborhood over a decade ago, I've occasionally tried to solve the mystery of the trestle's location and while stuck sick in bed after Thanksgiving, I picked up the puzzle again. Over the years, I've found several photos and maps that show the long lost trestle. I decided a map viewer that could overlay all the maps I've collected would help show how the area changed over the years and hopefully reveal the trestle's likely location.

While recovering in bed, I learned more about the math behind map projections than I expected, and ended up with a general purpose system that can now plot any map as a layer in a web based viewer called Map Table.

Map Table anchors any map to known geographic locations, and then generates map tiles to be viewed on top of OpenStreetMap data using Leaflet. Additional controls allow you to adjust each map's opacity and visibility so you can easily combine maps to see their similarities and differences.

The quest to conclusively identify the trestle's location continues, but in the meantime you can explore a bit of Oakland history yourself using Map Table.

If you are interested in using Map Table for yourself, the source code is available on GitHub.