Water working slowly over the ages is the sculptor of Lehman Caves. The beginning of Lehman Caves can be traced back to approximately 600 million years ago, in the early Cambrian period. Much of what is now Nevada and western Utah was covered by a warm, shallow, inland sea.  During this time, many thick layers of sediment accumulated on the sea bottom. Some of the layers were composed of silt, some were sand, and still others were made up of a limy substance that originated from decomposed bodies of minute shell creatures.

One of these limy layers was to become the marble in which Lehman Caves formed. This limy layer was compacted greatly by the weight of latter sediments deposited upon it. Under this pressure, the limy layer slowly turned to limestone rock. Later, as pressure and heat increased, the limestone turned to a low-grade marble.  Later, great forces under the earth's crust caused the layers of rock to buckle. This mountain range (the buckle) rose gradually until its peaks were thousands of feet above the valley floor. The rock layers cracked and fractured from the stresses of the uplift. In the future, the pattern of these fractures would help determine the floor plan of the cave.

Acidic ground water came from melting snow and rain. Pure water could not dissolve marble. This water absorbed carbon dioxide from the air and decaying vegetation in the soil, which generated carbonic acid. This weak acid dissolved out cavities in the marble bedrock. Eventually, the water level dropped, leaving air-filled passageways ready for the next stage of cave development.

Seeping water continues to enter the cave at a slow rate. The weak acid dissolves some of the bedrock above the cave and redeposits the mineral (calcite) on the floors, ceilings, and walls of Lehman Caves. Many of the beautiful formations in Lehman Caves are still growing, and are very fragile.  

> In Depth Geology of Lehman Caves