Colophon

About this guide

Who wrote it, how it's built, what it gets wrong, and where corrections go.

This is a field guide to San Mateo, California, written for people who live here or are about to. It is organized by elevation, west to east, because that is the variable that changes across this city: the fog, the temperature, the lot sizes, the walk to a train.

What it is not

It is not a real estate site, a chamber of commerce page, or a list of the twenty best restaurants. Restaurant lists rot, attendance areas get redrawn, and train timetables change — this one changed substantially when the line was electrified. Where a detail is the kind that moves, this guide names the source rather than freezing a number in place.

Anything a decision rests on is worth checking at the source, especially:

• School attendance areas, with the district, for the exact address.
• Caltrain and SamTrans schedules, with the current timetable.
• Flood zones, insurance, and levee planning east of 101, with the city and an insurer.
• Permit requirements, with the city's building counter.

How it's built

Jekyll, plain Markdown, hand-written CSS, no framework and no tracking. Every neighborhood is a Markdown file carrying its coordinates and its elevation, and everything else is generated from that: the maps, the cross section, the band lists. Adding a neighborhood adds a marker and a dot.

The maps are Leaflet over OpenStreetMap tiles — open source, no account, no key, and the library is served from this site rather than a CDN. Neighborhood pins are anchors rather than surveyed centres: a school, a park, a station, or the middle of the tract, checked against OSM. Boundaries between neighborhoods here are argued about by residents and were never official to begin with.

The cross section is drawn by hand from an elevation table. Its vertical scale breaks at 60 ft — the first 60 feet get more of the drawing than the remaining 500 — because otherwise eight of the eleven neighborhoods pile into fifteen pixels at the bottom. The caption on the drawing says so.

The palette comes from the ground it describes: the teal of Crystal Springs Reservoir, the grey-green of the marine layer, the gold of summer hills, and the pink of the salt evaporation ponds on the Bay.