Michigan division_area

[PeterTWNLUS]

wrt division_area:

Michigan division_area data includes the Great Lakes. Is there data available that just offers the outline of Michigan up until the lakeshores?
How does "is_land" work?

LOAD spatial;

SET s3_region='us-west-2';

COPY(
  SELECT
    geometry
  FROM
    read_parquet('s3://overturemaps-us-west-2/release/2026-02-18.0/theme=divisions/type=division_area/*', filename => true, hive_partitioning=1)
  WHERE
    subtype = 'region'
    AND country = 'US'
    AND region = 'US-MI'
) TO 'Michigan.geojson' WITH (FORMAT GDAL, DRIVER 'GeoJSON');

[Dana Bauer (danabauer)]

PeterTWNLUS Thanks for your question. Adding is_land=TRUE to your query won't help. The issue is with the data itself. The divisions team is aware of it and they're working on a fix. In the meantime, you could run this query to get all the county polygons in Michigan clipped to the coastline:

COPY(
    SELECT
      geometry
    FROM
      read_parquet('s3://overturemaps-us-west-2/release/2026-02-18.0/theme=divisions/type=division_area/*', filename => true, hive_partitioning=1)
    WHERE
      country = 'US'
      AND region = 'US-MI' AND admin_level=2
  ) TO 'Michigan-all-counties.geojson' WITH (FORMAT GDAL, DRIVER 'GeoJSON');