The county park shapefiles from #5 use EPSG:2227 (California 3) as their projection.

I had to hack the script around to import the data correctly. I replaced 4326 with 2227 in a couple of places:

Then to get the data to show correctly as a GeoJSON-powered map I had to use this in the queries:

select AsGeoJSON(Transform(geometry, 4326)) as geojson ...

Demo: https://santa-clara-county-parks-j7hipcg4aq-uc.a.run.app/parks/park_boundary_maps