size. It holds a variety of rare speleothems, including lemon-yellow sulfur deposits, gypsum chandeliers, gypsum hairs and beards, soda straws, hydromagnesite balloons, cave pearls, subaqueous helictites, rusticles, U-loops, and J-loops. Lechuguilla Cave surpasses nearby Carlsbad Caverns in size, depth, and variety of speleothems, though no room has been discovered yet in Lechuguilla Cave that is larger than Carlsbad's Big Room. For the first time, a Guadalupe Mountains cave extends deep enough that scientists may study five separate geologic formations from the inside. The profusion of gypsum and sulfur lends support to speleogenesis by sulfuric acid dissolution. The sulfuric acid is believed to be derived from hydrogen sulfide that migrated from nearby oil deposits. Therefore, this cavern formed from the bottom up, in contrast to the normal top-down carbonic acid dissolution mechanism of cave formation. Lechuguilla Cave lies beneath a park wilderness area. The cave's passages may extend out of the park into adjacent Bureau of Land Management (BLM) land. A major threat to the cave is proposed gas and oil drilling on BLM land. Any leakage of gas or fluids into the cave's passages could kill cave life or cause explosions. Microbiology Rare chemolithoautotrophic bacteria are believed to occur in the cave. These bacteria feed on the sulfur, iron, and manganese minerals and may assist in enlarging the cave and determining the shapes of unusual speleothems. The claim in the BBC documentary series Planet Earth that these bacteria do not derive any energy from the sun is incorrect, in that sulfur-oxidizing bacteria found in the cave use atmospheric oxygen (derived from sunlight-driven photosynthesis) as an electron acceptor, with the electron donor (source of energy) derived from dissolved groundwater hydrogen sulfide gas. Other studies indicate that some microbes may have medicinal qualities that are beneficial to humans. Some of the bacterial strains isolated from the cave have been found to harbor novel pathways for antibiotic resistance. A 4 million year-old strain of Paenibacillus isolated from soil samples in Lechuguilla Cave was found to be naturally resistant to many modern antibiotics, including daptomycin. Filming The Denver Museum of Nature and Science filmed one of the first documentaries in the cave, titled Lechuguilla Cave: The Hidden Giant, in 1987, featuring many of the cavers responsible for the breakthrough and initial survey work. The video was broadcast on the Denver PBS station KRMA-TV in 1989. The 1992 National Geographic Society program titled Mysteries Underground