Below Missouri Karst

Imagine a landscape marked by limestone and dolomite ridges, dry hollows, caves, sinkholes, big springs, natural bridges and streams that sink into their own beds. That's Missouri karst! The word "karst" comes from the German for the limestone region of Krs, Slovenia. Missouri is known as The Cave State because of its large number of caves. At least 5,700 caves are recorded in the Missouri Speleological Survey's files in Rolla. Tennessee exceeds our count with 7,000 caves, but people discover about 125 new caves each year in Missouri. Certainly our caves are among the largest and most spectacular in the nation. There are caves in 78 of our 114 counties, mostly in the Ozarks, but some as far north as Hannibal.

Many of our ancient caves have passed through several lifetimes of development, starting with the dissolving action of slightly acidic groundwater on fractured bedrock. This natural plumbing enlarged because of collapse, canyon cutting by internal streams, accumulation of clays and gravels and re-excavation by streams. Drippings of flowing water laden with dissolved rock deposited calcite in these openings. The eventual fate of a cave is to erode away, as illustrated by natural bridges.

These events ranged over huge spans of time. The sea deposited Missouri's oldest cavernous rocks around 500 million years ago during the Cambrian Period.

The Gasconade Dolomite of the Ordovician Period (around 450 million years old) is the most cavernous rock formation in Missouri.

In the Mississippian Period (about 350 million years ago), marine organisms created the Burlington/Keokuk Limestones which today are highly cavernous around Springfield, Columbia and northeastern Missouri. By the time the Cenozoic Era began 66 million years ago, Missouri had dolomite and limestone up to 1500 feet thick. At present, karst is developing rapidly, as evidenced by our large, deep springs and numerous losing streams.

The Perryville karst in Perry County has about 650 known caves, the most of any county in Missouri. The caves are large, complex, flood-prone systems, and groundwater contamination is a growing problem in this area. Crevice Cave is the longest in the state at 28.2 miles. Berome-Moore Cave is an extensive system in which ancient cat tracks have been found.

The Springfield Plateau contains hundreds of relatively younger caves. Expanding urban areas threaten groundwater and the endangered Ozark cavefish. Some caves have beautiful speleothems, despite all the mud, and cave structures tend to be fairly simple.

The largest continuous karst terrain is in south-central Missouri. The