Wind Cave National Park

Lore & Background

Wind Cave National Park, located north of Hot Springs in western South Dakota, features a remarkable cave system known for its distinctive calcite formations, including boxwork and frostwork. The park contains approximately 95 percent of all discovered boxwork formations in the world. The cave is recognized as the densest cave system globally, with the greatest passage volume per cubic mile, and ranks as the sixth longest cave worldwide and the third longest in the United States, though it is only the second longest in Custer County, South Dakota, behind Jewel Cave. Despite their proximity, no connection has been found between Wind Cave and Jewel Cave, and most geologists believe they are not linked. Above ground, the park protects the largest remaining natural mixed-grass prairie in the United States and serves as the southern terminus of the South Dakota Centennial Trail. The cave is a classic example of a "breathing cave," where air moves in or out to equalize atmospheric pressure with the outside. Rapid weather changes in western South Dakota cause barometric shifts that produce the strong winds at the cave's entrance, for which it was named. The Lakota people originally called it Washun Niya and considered it a sacred site where they first emerged from the underworld.

Reader's Guide

Wind Cave National Park holds significance as the sixth national park in the U.S. and the first cave anywhere in the world to receive that designation. Its cave system is recognized as the densest in the world, with the greatest passage volume per cubic mile, and is the sixth longest cave globally. The park protects the largest remaining natural mixed grass prairie in the United States and hosts a diverse ecosystem including bison, elk, and endangered species such as the black-footed ferret and whooping crane. The Wind Cave bison herd is one of only four free-roaming, genetically pure herds on public lands in North America. The cave's breathing phenomenon, caused by air pressure equalization, gave it its name.

Did You Know?

• Wind Cave is the third longest cave in the United States but only the second longest in Custer County, South Dakota, behind Jewel Cave.
• The cave is named for the wind created when air rushes out of its openings to equalize atmospheric pressure.
• Approximately 95 percent of the world's discovered boxwork formations are found in Wind Cave.
• The South Dakota Centennial Trail passes through the park, but its southern terminus is at the South Dakota/Nebraska border.

Geological Marvels and Global Distinction

Wind Cave occupies a singular position among the world's subterranean systems. It is recognized as the densest cave system on Earth, holding the greatest passage volume per cubic mile of any known cave. As of 2025, explorers have mapped 168.02 miles (270.40 km) of passageways, placing it as the sixth longest cave globally and the third longest in the United States. Within Custer County, South Dakota, it ranks second behind Jewel Cave, though geologists largely believe the two systems remain unconnected despite their close proximity. The cave's interior showcases calcite formations called boxwork alongside frostwork structures. Remarkably, roughly 95 percent of all boxwork formations discovered worldwide are found within Wind Cave's passages, making it the definitive location for studying this rare mineral architecture. Above ground, the park preserves the largest remaining natural mixed grass prairie in the country and marks the southern terminus of the South Dakota Centennial Trail.

Sacred Origins and Indigenous Dispossession

Long before any Euro-American settler set foot near the cave, the Lakota people regarded the site as profoundly sacred. Known to them as Washun Niya, the cave featured in their creation narrative as the place where Tokahe, the first human, emerged from the underworld into the newly formed world. The cave and its surrounding terrain also served as a practical resource hub—euphemistically called a "supermarket"—where winter camps thrived and game animals sought shelter, making the area ideal for hunting and settlement. The Lakota, Cheyenne, and other tribes who traveled through the Black Hills were aware of the cave's existence, though no recorded evidence confirms anyone actually entered it. The eventual loss of these lands followed a familiar pattern: the 1868 Treaty of Fort Laramie reduced Lakota territory, Custer's 1874 survey falsely reported gold, miners invaded in violation of treaty terms, and the 1877 Dawes Act opened the site to settlers, effectively severing the Lakota from their ancestral ground.

Discovery and the McDonald Era

The first documented encounter with Wind Cave by white Americans occurred in 1881, when brothers Tom and Jesse Bingham noticed wind rushing from a small hole measuring roughly 10 by 14 inches in the prairie. According to the account, Tom peered into the opening and the force of the exiting air knocked his hat clean off his head. For the next eight years, few ventured far inside. In 1889, the South Dakota Mining Company hired Jesse D. McDonald to oversee a mining claim on the site, possibly hoping to find valuable minerals or perhaps already envisioning commercial tourism. When no mineral deposits materialized, the McDonald family pivoted to developing the cave for visitors. Alvin McDonald, just sixteen in 1890, and his brother Elmer, who joined in 1891, became central to exploration, with Alvin keeping a detailed cave diary. By February 1892, guided tours were underway—candlelit, physically demanding expeditions that sometimes required crawling through tight passages, all for a one-dollar fee.

The Breathing Cave and Its Name

Wind Cave earns its name from a phenomenon that makes it one of the best-known examples of a "breathing cave" in the world. Air continually flows in and out of the passages, equalizing the cave's internal pressure with the atmosphere above. When outside pressure exceeds the cave's internal pressure, air rushes inward; when the reverse occurs, air surges outward. Because Wind Cave is vast yet possesses only a handful of small openings, this breathing effect is far more pronounced than in smaller caves with many large entrances. The weather patterns of western South Dakota, characterized by rapid barometric shifts, amplify the effect. It is widely theorized that a fast-moving storm was approaching on the day the Bingham brothers first noticed the cave in 1881. The rapidly dropping atmospheric pressure would have forced the cave's higher-pressure air to blast out of every available opening, producing the dramatic gust of wind that gave the cave its enduring name.