How do I get the geometric data of an area?

The bokeh manual on bokeh.sampledata has Geometry data for US States. I have a question, how did I get such a file, I really want to create a similar file for several islands

@Aleksei3012 I added that file originally almost ten years ago, before we became more careful about documenting the provenance of sample data. I am afraid I don’t recall where it came from at all. If you have GeoJSON data for the islands, then the more recent GeoJSONDataSource might be the simplest route. Otherwise you would need to convert whatever GIS data you have for the islands to the more low level representation that MultiPolygons.