The Lost River Spring illustrates how groundwater can resurface without warning, creating unique features at Lost River Cave.

It is estimated that only about 20% of the entire United States is classified as karst. Karst is a distinctive topography in which the landscape is largely shaped by the dissolving action of water on carbonate bedrock. Here at Lost River Cave the carbonate bedrock is limestone. Over many thousands of years the turbulent groundwater dissolves this limestone, creating unusual surface and subsurface features. Sinkholes, vertical shafts, disappearing streams, springs, complex underground drainage systems and caves stand as testament to this ongoing geological process.

Water naturally utilizes any cracks or crevices in the rock as gravity pulls the water underground. Over long periods, with a continuous supply of water rich in Carbon Dioxide, openings in the bedrock increase in size and an underground drainage system begins to develop, allowing more water to pass, further accelerating the formation of karst. The sinkholes, collapsed cave valley, cave, river and blue holes at Lost River are all tangible evidence of the vast, underground dissolved limestone drainage system that sits beneath this region of Kentucky, shaping the lives of those who live here.

Blue Holes are karst "windows" peeking into the underground drainage system.

Karst groundwater provides drinking water, springs to feed our waterways and habitat for many unusual subterranean species. Unfortunately, due to the quick drainage of rainwater
directly into sinkholes, the rivers and springs in such areas are easily contaminated. Storm water run-off crosses roadways, gas stations, farms and residential areas before flowing into Kentucky cave systems. Residents must be vigilant and work together to protect the water entering the ground.

Building on karst is another task that requires citizens to be cautious and knowledgeable about their environment. Surveys must be conducted to ensure that sinkholes are not likely to form under manmade structures. Sinkholes are caused by either a collapsed cave or the loss of topsoil into a karst crevice. Houses, businesses and roadways have been lost to sinkhole collapse in karst regions throughout the United States. Lost River Valley actually began as a collapsed portion of cave. The basin collects drainage from the surrounding 55 square miles. After the major breakdown, large volumes of water flowed into the trench--carrying with it soil and plant material and eventually creating the wooded valley visitors enjoy today!

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