This would eventually be a posible hypothetical map of how california would have become a country

I’ve been stumped over this. Is this migration of some bird or animals? Maybe ocean current? It doesn’t resemble any map I’ve seen, and there’s no legend.

Each white colored pixel should represent 10000 people. Pixels do not stack. For further questions, feel free to ask!

Made with data from opentransportdata.swiss, download.geofabrik.de (OpenStreetMap map tiles), and help from Claude.