One such company mined a 26-acre farm in Lisbon earlier this year.
The company, which owns more than 100,000 acres, is now mining and reclaiming other adjacent areas.
During its 93 years history (1914-2007), the company mined about 370 Mtonnes of coal.
And the big companies are mining gold at a record rate from public land without paying a dime in royalties.
The company mined the borax for about 10 years.
Smith has said that his company was "mining more than a million tons of a coal" per year and employed over 100 people.
In 1869, a company was mining in the area.
The company had mined vast amounts of gypsum found in the area.
But some environmental groups have suggested that the company mined too heavily to meet last winter's demand.
Two companies mined for argentiferous galena, a source of silver.