a) In Montana as elsewhere, companies that have acquired older mines respond to demands to pay for cleanup in either of two ways.
d) Especially if the company is small, its owners may declare the company bankrupt, in some cases conceal its assets, and transfer their business efforts to other companies or to new companies that do not bear responsibility for cleanup at the old mine.
c) If the company is so large that it cannot claim that it would be bankrupted by cleanup costs, the company instead denies its responsibility or else seeks to minimize the costs.
b) In either case, either the mine site and areas downstream of it remain toxic, thereby endangering people, or else the U.S. federal government and the Montana state government pay for the cleanup through the federal Superfund and a corresponding Montana state fund.