timber, for grazing purposes, as a source of clean water, as a location for recreational activities, as wildlife habitats and scenic areas, and for other purposes.

Mining inevitably affects these resources. The significance of potential negative impacts depends on the extent to which they can be avoided or mitigated. This, to some extent, depends on compliance with regulations. Mining, its impacts on other resources and uses, and the regulatory structure are related matters that require balance and reason when dealing with the potentially competing issues of protection of the environment, production of minerals and metals and employment for society, and associated federal and state statutory responsibilities.

This report is particularly timely in that the BLM has proposed to revise its regulations for hardrock mineral exploration and development conducted under the authority of the General Mining Law of 1872. Because the Committee's charge stated that the baseline for the study was the existing regulatory framework rather than proposed changes to that framework, the Committee did not focus on the BLM proposal to revise its regulations. The Committee was told that the Forest Service was also internally considering revisions in its regulations for hardrock mining in national forests, but the Committee has not reviewed any of the changes being considered.

The Committee's conclusions and recommendations are based on information obtained in a series of presentations and open public forums at Committee meetings in Washington, D.C., Denver, Reno, and Spokane. Committee members also made visits to a variety of mining operations in Colorado, California, Nevada, Washington, and Alaska. The Committee also was helped in its work by a large volume of reports, submissions to the Committee, and copies of submissions to the BLM in connection with the proposed revision of its hardrock mining regulations. The Committee itself represented a wide spectrum of skills and experience relevant to mining on federal lands.

HARDROCK MINING AND THE ENVIRONMENT

Hardrock mining occurs where minerals are concentrated in economically viable deposits. Ore deposits form as variants of such geologic processes as volcanism, weathering, and sedimentation operating with an extraordinary intensity. Ore deposits typically are parts of large-scale (several miles across and perhaps just as deep) ore-forming systems in which many elements, not just those of economic interest, have been enriched. Only a very small portion of Earth's continental crust (less than 0.01%) contains economically viable



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