Decorah Ice Cave State Preserve has one of the largest

ice cave An ice cave is any type of natural cave (most commonly lava tubes or limestone caves) that contains significant amounts of perennial (year-round) ice. At least a portion of the cave must have a temperature below 0 °C (32 °F) all ye ...

s in the

Midwestern United States The Midwestern United States (also referred to as the Midwest, the Heartland or the American Midwest) is one of the four census regions defined by the United States Census Bureau. It occupies the northern central part of the United States. It ...

. It consists of a parcel of land at the edge of Barbara Barnhart VanPeenen Memorial Park in the northern portion of the city of

Decorah Decorah is the largest city in and county seat of Winneshiek County, Iowa, United States. The population was 7,587 at the time of the 2020 census. Decorah is located at the intersection of State Highway 9 and U.S. Route 52. Located within the ...

, in Winnesheik County,

Iowa Iowa ( ) is a U.S. state, state in the upper Midwestern United States, Midwestern region of the United States. It borders the Mississippi River to the east and the Missouri River and Big Sioux River to the west; Wisconsin to the northeast, Ill ...

. Ice Cave is open to the public as an 'enter at your own risk' attraction. In the late 1990s, the Department of Natural Resources Geological Survey Bureau required a permanent barrier be installed due to some rock movement. Since then, a large rock has fallen and visitors are now only able to comfortably walk into the cave about 10 feet from the entrance. Ice caves are one characteristic of

karst topography Karst () is a topography formed from the dissolution of soluble carbonate rocks such as limestone and Dolomite (rock), dolomite. It is characterized by features like poljes above and drainage systems with sinkholes and caves underground. Ther ...

, along with

sinkhole A sinkhole is a depression or hole in the ground caused by some form of collapse of the surface layer. The term is sometimes used to refer to doline, enclosed depressions that are also known as shakeholes, and to openings where surface water ...

s and cave systems, all of which are present in the area, a portion of the

Driftless Area The Driftless Area, also known as Bluff Country and the Paleozoic Plateau, is a topographic and cultural region in the Midwestern United States that comprises southwestern Wisconsin, southeastern Minnesota, northeastern Iowa, and the extreme ...

of Iowa. From autumn and into early winter the cave is dry. Ice begins to form in January or February near the entrance and continues down to the lower levels. Several inches of ice on the north wall materializes by late May, and generally remains until late August. The cave was given to Decorah in 1954 and remains the property of the city. It was declared a state geological state preserve in 1973. It was placed on the

National Register of Historic Places The National Register of Historic Places (NRHP) is the Federal government of the United States, United States federal government's official United States National Register of Historic Places listings, list of sites, buildings, structures, Hist ...

in 1978.

References

National Register of Historic Places in Winneshiek County, Iowa Parks on the National Register of Historic Places in Iowa Iowa state preserves Driftless Area Protected areas of Winneshiek County, Iowa Caves of Iowa Ice caves Protected areas established in 1973 Protected areas established in 1954 Show caves in the United States Natural features on the National Register of Historic Places Landforms of Winneshiek County, Iowa 1973 establishments in Iowa {{US-cave-stub