Cave and Karst Management
Cave: The Federal Cave Resources Protection Act of 1988, 16 U.S.C. §§ 4301-4310 (1994) (FCRPA), defines a cave as "any naturally occurring void, cavity, recess, or system of interconnected passageways beneath the surface of the earth or within a cliff or ledge that is large enough to be traversed by people, whether or not the entrance is naturally formed or manmade." The term includes any natural pit, sinkhole, or other feature that is an extension of the entrance. There are at least 23 types of caves, including lava tubes, solutional caves in limestone and gypsum, tectonic fractures (earth cracks), littoral (sea) caves, ice caves, and talus caves. It is strongly recommended that cave specialists be involved in cave assessment and inventory.
The FCRPA definition does not establish quantitative parameters for identification of a cave. Any one or a combination of the following criteria should be used to define a cave: a total passage length of at least 50 feet, contains areas of total darkness, and/or the length of the cave passage exceeds the width of the entrance.
Features that do not meet these criteria should be listed as "karst features" or another appropriate geologic term, and should still be managed with an appropriate degree of protection.
Off-trail: Sections of the cave that are beyond developed portions of a cave. These areas may have preferred routes of travel marked with flagging tape or some other marker to reduce impact to the cave features.
Rock shelter: A concavity in rock that may not have extensive passageways but has a large enough cavity or rock overhang to provide shelter for humans. Rock shelters are generally wider than they are long and usually do not extend into total darkness.
Karst: A landform comprised of sinkholes, sinking streams, zones of infiltration, underground passageways or watercourses, and spring resurgences, usually occurring in a soluble rock such as limestone or gypsum.
Sinkhole: A depression or pit in the earth caused by the chemical dissolution of rock, and/or the collapse of an underlying cave passage. Sinkholes may or may not become cave entrances.
Speleothem: A secondary mineral deposit that occurs in a cave, such as a stalactite, stalagmite, flowstone, or helictite.
Speleogen: Relief features on the walls, ceiling, and floor of any cave or lava tube that are part of the surrounding bedrock, including but not limited to, scallops, meander niches, and rock pendants in solution caves and similar features unique to volcanic caves.
Inventory: The systematic documentation of cave resources, usually linked to a coordinate system via survey stations. Managers have historically used two different kinds of inventories: an inventory of caves and an inventory of the contents of caves.Cave and Karst Management Table of Contents | RM#77 Table of Contents