Official Site: https://www.nps.gov/wica/index.htm
Wikipedia: https://en.wikipedia.org/wiki/Wind_Cave_National_Park
Facebook: https://www.facebook.com/WindCaveNPS
From Wikipedia:
The Lakota, Cheyenne, and other Native American tribes who traveled through the area were aware of the cave's existence, as were early Euro-American settlers, but there has been no evidence yet discovered that anyone actually entered it.
The Lakota (Sioux), an indigenous people who live in the Black Hills region of South Dakota, spoke of a hole that blew air, a place they consider sacred as the site where they first emerged from the underworld where they had lived before the demiurge creation of the world.
National Park Service
http://www.nps.gov/wica/historyculture/upload/-11D-14-Chapter-Fourteen-Wind-Cave-Pp-530-577-2.pdf
National Park Service
https://www.nps.gov/wica/learn/news/upload/Wind-Cave-NP-Newspaper-2015.pdf