Underground Coal Mining

This U.S. industry comprises establishments primarily engaged in one or more of the following: (1) underground mining of bituminous and anthracite coal; (2) developing bituminous and anthracite coal underground mine sites; and (3) underground mining and beneficiating (e.g., cleaning, washing, screening, and sizing) of… It has no schema of its own: companies here are mapped on the Universal schema, and what it does not cover is recorded as gaps.