FACT SHEET The first documented exploration of Black Chasm Cavern was by several miners and a journalist in 1854. Armed with several pounds of candles to place in the soft clay, and a very long rope, they began their descent to the unseen depths below. The journalist described that "the courage of the first to descend was rather a matter of unconsciousness of danger, than a knowledge of the situation and a willingness to face it," and that "as the size of the cavern, and the depth and almost perpendicular descent, became apparent by the lighted candles a hundred feet below, all except the advanced portion of the party beat a retreat." Those who continued were rewarded by spectacular views, such as "crystals, though formed of rhomboid spar, stood out from the walls in every conceivable direction, turning and bending into many shapes, according to the law of obtuse angles." Given its perpendicular orientation, it took a while before someone was adventurous enough to build a trail into Black Chasm Cavern. The first tours were given by a miner in the 1860s who built redwood decking into the first room, which eventually collapsed. Black Chasm Cavern is located on land that used to be part of the quarry next door. The cave was slated to be quarried for calcite by the previous owners sometime in the late 1960s to early 70s. Fortunately, the price of calcite dropped drastically, making the quarry project unfeasible. During the 1960s, the National Speleological Society made several exploratory dives into the cave and noted its extraordinary speleothem (formation) diversity. After hearing about the quarrying plans, they decided to see if they could protect the cave by recommending it for National Natural Landmark status. When a representative from the National Park Service came to inspect the site, he agreed that this was something special that should be protected for future generations, and filed his report in 1970. Black Chasm Cavern received its National Natural Landmark status in 1976. This is a designation that can be ascribed to privately owned places of national geological and ecological significance. Black Chasm Cavern was noted as being "...the outstanding helictite cave in the far West." Sierra Nevada Recreation Corporation purchased Black Chasm Cavern 1996. For a couple of years wild cavern expeditions were offered in the undeveloped cave. Construction of the new trail into Black Chasm Cavern was begun in mid-2000. The current long-lasting, corrosion-resistant stairways and trail were first opened for public walking tours on September 30, 2000. Early guests had the chance to see the innovative platform, stair and walkway system being built into the cave using non-biodegradable materials. This was completed by April 16, 2001 when the 45-minute Landmark Tour was offered, taking guests through to the Landmark Room which contains masses of rare helictite crystals. Helictite crystals like those found in Black Chasm Cavern are very rare and occur in approximately 5% of caves worldwide. Unlike most cave formations (speleothems) helictites are not formed by dripping or flowing water, but by hydrostatic pressure. Water under pressure pushes through the cave wall into the chamber depositing minerals helically, forming the characteristic spaghetti shape that grows horizontally from the walls.