All caves on the Karst Preserve were discovered in sinkholes. Because of the unstable nature of sinkholes it was necessary to create man-made entrances to many of the caves.

In addition to providing safe access, man made entrances are bone dry and do not allow water intrusion into the caves, unlike natural sinkhole entrances.

This is how most of the caves on the Cave Farm were found.  Sinkholes were excavated by hand, using shoring along the way. 

Today the Karst Preserve utilizes its very own trackhoe.

This machine was extensively modified to reach depths of 25 feet.

If a man made entrance becomes necessary, a suitable site must be located inside and outside the cave. Dave Gerboth stands where a future man made cave entrance will be installed.

A special cave radio will be utilized to determine the exact location and depth.   This is the antenna, which is positioned inside the cave.

After a backhoe removes soil to the bedrock, blasting begins. The scaffolding was setup to raise buckets of blast debris.

If an entrance shaft exceeds 50 feet a well drilling firm is contracted to drill the access shaft.

See Goliath's Cave, Cold Water Cave, Tyson Spring Cave and Bat River Cave

The access hole through the bedrock must be blasted all the way down into the cave and must be kept 30 inches in diameter. This process may take 2-3 months. 

When the blasted hole has finally reached the cave ceiling a culvert pipe is lowered down and placed on top of the bedrock.  It rests right on the hole we blasted.

After grouting has taken place to provide a watertight seal, backfilling can begin as shown in this photo.

A custom made steel ladder (usually 40 - 50 feet) is installed and a lockable lid is attached to the top of the culvert.

Then the entire site is back-filled with dirt and the area is seeded with natural grasses.  This completed entrance is 44' from the top of the culvert to the floor of the cave.

There are 15 culvert entrances on the Cave Farm, not including Spring Valley Caverns. The deepest man-made entrance required blasting to 58 feet.  Due to its length, Spring Valley Caverns has three such remote entrances in addition to the main building entrance.

The main entrance into Spring Valley Caverns lies deep inside this newly constructed 3 level building.   This expensive all concrete building has the appearance of hand laid limestone block.  The structure measures 22 x 40 feet and is 38 feet tall.  Most of the building is not visible because it was built below the surface, around three cave passages.