There are hundreds of caves in the Black Hills. One of the longest is in Wind Cave National Park at 141 miles. Amazingly, this is in a 1 square mile area, as the cave has multiple levels.
The “wind” is created by the change in barometric pressure. The air in the cave tries to equalizes with the are on the outside. Therefore, sometimes the wind is going in, and sometime out. Today, it was blowing out.
Otherwise, a cave is a cave.