You can string together multiple place URLs. More info on that here:
https://forum.inaturalist.org/t/how-to-use-inaturalists-search-urls-wiki/63
Some western states:
https://www.inaturalist.org/observations/identify?place_id=46,10,14,22,15,16,34,50,52,9,40
https://www.inaturalist.org/observations?place_id=46,10,14,22,15,16,34,50,52,9,40
I think large places can be cumbersome on the server, so these alternatives are probably the best options.