Activists are concerned about the Mining Law of 1872 which was passed by Congress in an era when they wanted to encourage exploration, investment and settlements in the wide open West.

Groups like Earthworks say the law has been a "taxpayer ripoff" because companies have made billions of dollars but don't pay a fair amount in taxes, royalties or environmental clean up once the mines have closed.

They are supporting a proposed congressional bill which would place new restrictions like mining in National parks or wilderness areas. But supporters of the mining industry say companies have contributed billions of dollars to the US economy, face strict environmental regulations and are making more positive changes.

Earthworks Arizona Mining Association