Trailer tails

The longest cave system in the world is a 390-mile-long, multilevel scene of dissolution and beauty known as Mammoth Cave, one of Kentucky's 3 geo-sites, which we visited today.  Not being a lover of small, enclosed, spaces, I wasn't looking forward to this particular National Park, but, if Mr. Spock was going, so was I.

South-central Kentucky is built on a solid base of limestone, deposited within a shallow sea that inundated the southeastern U.S. during the early Carboniferous period. Over the last 20 million years, groundwater charged with carbonic acid - the same acid found in soft drinks - has slithered through cracks and fissures in this bedrock gradually enlarging the microscopic passages into ever-larger voids that eventually became today's cave systems.

Prehistoric peoples explored 10 or more miles of Mammoth Cave 4,000 years ago. Archeological evidence show that these early cavers collected crystals and other salts in the cave. Cave exploration ceased 2,000 year ago, and for unknown reasons, did not resume until the cave was rediscovered in 1798.

It was not a crowded day at Mammoth Cave.

There are a variety of tours available and we selected the Frozen Niagara Tour. This is Ranger Dave who was our tour guide. 

The entrance to the Frozen Niagara Tour. Looks ominous.

You are not allowed to use flash on your camera, but Ranger Dave had a flashlight that worked to illuminat Mr. Spock as he inspected the rocks.

We were in the "dry" part of the cave system.

There were five other people with us on the tour, part of which descends under the Frozen Niagara formation. Many of them used their cell phone lights to illuminate Spock deep underground.

We also took picture of each other - it was a real group undertaking.

These are cave crickets that were on the ceiling of the cave. They are about 2 inches long.

A display in the Visitor Center showed the network of discovered caves. Geologists believe that there are another 600+ miles of caves to be discovered.

Another exhibit in the Visitor Center showing how the caves were formed.

We have been traveling Interstate #65 and so have the trucks. 

We have noticed these aero-dynamic truck appendages before but only when we were towing so we couldn't get a good picture. They are called "trailer tails".