When developing federal public lands, mining companies can take advantage of two federal laws. First, under the 1872 Mining Law, companies can mine "hard rock" minerals, such as gold, silver, platinum, and copper, without paying the royalties the federal government charges for other types of minerals extracted from public lands, such as oil, gas, or coal. Not only do these companies get the minerals for free, but they are also able to buy the land bearing the minerals by patenting it for as little as $2.50 an acre.

Second, a special rule under the tax code called the "percentage depletion allowance" permits mining companies to deduct a percentage of their taxable gross income from the federal taxes they must pay. The deduction is intended to reflect the reduction in the value of the mineral deposit over time as minerals are extracted. But since, under the 1872 Mining Law, mining companies pay nothing to obtain publicly owned minerals, these tax deductions allow the mining industry to get publicly owned minerals without cost and receive a tax break to mine them.

These subsidies encourage mining operations that would otherwise be economically impracticable, often leaving badly scarred landscapes and polluted rivers and lakes. Many mining sites are listed as hazardous waste sites under Superfund, with cleanup costs estimated in the billions of dollars.

During Senate consideration of the Fiscal Year 1999 budget resolution, Sens. Dale Bumpers (D-AR) and Judd Gregg (R-NH) offered an amendment to repeal the percentage depletion allowance for mining on public lands and to redirect the revenue generated toward special education programs proposed in President Clinton's Fiscal Year 1999 budget. According to the Office of Management and Budget, repeal of this corporate subsidy for non-fuel minerals mined on federal lands would generate $294 million over the next five years.

On April 2, 1998, the Senate approved a motion by Sen. Pete Domenici (R-NM) to table (kill) the Bumpers/Gregg amendment, 55 - 44. NO is the pro-environment vote.