As used in this chapter:
"Coal" means any of the recognized classifications and ranks of coal, including anthracite, bituminous, semibituminous, subbituminous, and lignite.
"Outcrop" means any place where a formation is visible or substantially exposed at the surface.
"Formation" means any vein, seam, stratum, bed, or other naturally occurring deposit.
"Coal mine" means any underground, surface, or strip mine from which coal is obtained.
"State" means any State or Territory of the United States, or any political subdivision thereof.
"Person" means an individual, partnership, association, corporation, business trust, legal representative, or any organized group of persons.
(Aug. 31, 1954, ch. 1156, §2, 68 Stat. 1009.)