This has been discussed at length many times. It’s worth the time going through these posts to get a background of what’s already been discussed:
- https://forum.inaturalist.org/t/help-with-adding-a-level-iv-ecoregion/31138
- https://forum.inaturalist.org/t/visualize-ecoregions-as-map-background/32081
- https://forum.inaturalist.org/t/adding-subdivisions-of-california-floristic-provinces/1268/12
- https://forum.inaturalist.org/t/observing-entire-ecosystems/19103/23
- https://forum.inaturalist.org/t/adding-bioregions-to-location-filters-for-projects/20181/2
- https://forum.inaturalist.org/t/is-there-any-way-to-add-extra-layers-overlays-to-the-maps-on-inaturalist/21983
- https://forum.inaturalist.org/t/favorite-most-wanted-ecosystems/39104/6
- https://forum.inaturalist.org/t/how-to-browse-regions-create-new-regions-learn-about-regions/10129
- https://forum.inaturalist.org/t/add-us-epa-ecoregions/10307
- https://forum.inaturalist.org/t/implement-standard-marine-places-for-the-worlds-oceans/1458/6