of critical minerals in coordination with the Bureau of Land Management. In response, a list of 35 critical minerals was compiled using a quantitative screening tool (Fortier and others, 2018). The draft list of 35 minerals or mineral material groups deemed critical was published in May 2018 by the Federal Register (Federal Register, 2018). A "critical mineral," as defined by Executive Order 13817, is a mineral (1) identified to be a nonfuel mineral or mineral material essential to the economic and national security of the United States; (2) from a supply chain that is vulnerable to disruption; and (3) that serves an essential function in the manufacturing of a product, the absence of which would have substantial consequences for the U.S. economy or national security. Disruptions in supply chains may arise for any number of reasons, including natural disasters, labor strife, trade disputes, resource nationalism, and (or) conflict. To address the new data needs in order to develop an inventory of the regions that are known to be, or may be, prospective for increasing the domestic supply of critical minerals, the U.S. Geological Survey developed the Earth Mapping Resources Initiative. The initiative forms a partnership among the U.S. Geological Survey, State Geological Surveys, and private industries to identify focus areas for new digital data acquisition to increase the understanding of where critical minerals may be prospective. The outcome of the effort is to enhance the understanding of the United States' prospectivity for knowing domestic mineral supply to help decrease our reliance on foreign sources of minerals fundamental to the Nation's security and economy.
