Maryland Code, Natural Resources § 5-1401

(a) In this subtitle the following terms have the meanings indicated.

(b) “Cave” means any naturally occurring void, cavity, recess, or system of interconnecting passages beneath the surface of the earth or within a cliff or ledge, including natural subsurface water and drainage systems. The word “cave” includes or is synonymous with cavern, sinkhole, grotto, and rock shelter.

(c) “Cave life” means any life form which normally occurs in, uses, visits, or inhabits any cave or subterranean water system, excepting, herein, those animals and species covered by any of the game laws of this State.

(d) “Commercial cave” means any cave with improved trails and lighting utilized by the owner for the purpose of exhibition to the general public as a profit or nonprofit enterprise, wherein a fee is collected for entry.

(e) “Gate” means any structure or device located to limit or prohibit access or entry to any cave.

(f) “Owner” means a person who has the right of access (or possession) to the cave.

(g) “Person or persons” means any individual, partnership, firm, association, trust, or corporation.

(h) “Sinkhole” means a natural depression in a land surface communicating with a subterranean passage or drainage system.

(i) “Speleogen” means an erosional feature of the cave boundary and includes or is synonymous with anastomoses, scallops, rills, flutes, spongework, and pendants.

(j) “Speleothem” means a natural secondary mineral formation or deposit occurring in a cave. This includes or is synonymous with stalagmites, stalactites, helectites, anthodites, gypsum flowers, needles, angel's hair, soda straws, draperies, bacon, cave pearls, popcorn (coral), rimstone dams, columns, palettes, flowstone, et cetera. Speleothems are commonly composed of calcite, epsomite, gypsum, aragonite, celestite and other similar minerals.