Niagara Cave is a

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...

cave located in Harmony, Minnesota. The cave is approximately 200 feet (61 m) deep; features include an underground stream, 60-foot waterfall, fossils, stalactites and

stalagmites A stalagmite (, ; from the Greek , from , "dropping, trickling") is a type of rock formation that rises from the floor of a cave due to the accumulation of material deposited on the floor from ceiling drippings. Stalagmites are typically ...

. The cave is privately owned, with tours available seasonally. The cave was first discovered in 1924, and in 1932, three

spelunkers Caving – also known as spelunking in the United States and Canada and potholing in the United Kingdom and Ireland – is the recreational pastime of exploring wild cave systems (as distinguished from show caves). In contrast, speleology is ...

Al Cremer, Leo Tekippe, and Joe Flynn explored the cave and named the site Niagara Cave. Niagara Cave opened as a show cave in June 1934, and was described by geologist

J Harlen Bretz J Harlen Bretz (2 September 1882 – 3 February 1981) was an American geologist, best known for his research that led to the acceptance of the Missoula Floods and for his work on caves. Early life and education Bretz was born on 2 September 188 ...

in 1938. The

Minnesota Geological Survey The Minnesota Geological Survey is a unit of the Newton Horace Winchell School of Earth Sciences at the University of Minnesota The University of Minnesota, formally the University of Minnesota, Twin Cities, (UMN Twin Cities, the U of M, or ...

noted in their 1995 survey, "Niagara Cave contains an excellent example of an underground river, complete with waterfall." Niagara Cave waterfall

References

Limestone caves Tourist attractions in Minnesota Caves of Minnesota Show caves in the United States {{Minnesota-stub