You might google Superfund sites in Montana [https://en.wikipedia.org/wiki/List_of_Superfund_sites_in_Montana https://en.wikipedia.org/wiki/List_of_Superfund_si

You might google Superfund sites in Montana [https://en.wikipedia.org/wiki/List_of_Superfund_sites_in_Montana https://en.wikipedia.org/wiki/List_of_Superfund_sites_in_Mon... ]. There is no shortage of towns that have been made uninhabitable, but perhaps not in densely populated areas.