Northern Arizona’s Lava River Cave

Lava River Cave was found by lumber workers in 1915, and used as a source of ice for refrigeration in the early 1900s; although local indigenous people almost certainly knew about it many centuries earlier.  But it all started around 700,000 years ago when a vent in a local shield volcano oozed lava across the surface.   As the outer sides and top of the lava flow cooled, the interior was insulated and continued to flow creating an underground river of lava.  Northern Arizona has many hidden lava tubes, and they are usually discovered only when a section of roof collapses to reveal the tunnel beneath.

Imagine you are a logger, working in the Ponderosa Pines of Northern Arizona and all of a sudden you feel a cool breeze.  It is July and you are curious as to the source of this refreshing touch of cold.  After a little exploration you find it, a hole in the ground, a glimpse into some unknown mystery.

As you venture into the unknown depths of this mysterious discovery you find clues about the formation of this unique volcanic feature.  There are no stalactites, but you will find lavacicles, small protrusions on the ceiling that formed as molten lava froze as it was dripping down.  These structures are very near the entrance of the cave and often covered with condensation.  As you shine your flashlight upon the ceiling it is as if you are looking at a blanket of crystals.  The entrance to the cave is rough, loose rock, and was originally the ceiling that has now collapsed, but venture in further and you come across the original floor, the smooth surface of a river of lava frozen in time.  This is a wonderful place to explore the scientific evidence of the origin of the volcanic lava flow.

Generally, when exploring caves, one must be aware of the tunnels and turns so as not to get lost.  With the Lava River Cave hikers are very fortunate, as there is only one tube that is pretty straight except for one section where the passageway splits.  With a ceiling at almost forty feet in height hikers need to decide in which direction to proceed.  To the right you will have to crawl, to the left walk upright.  I choose to go to the left but many children love the excitement of the right.  Both routes connect again and we continue on our adventure of discovery.

As we proceed into the dark, past cooling cracks and splash downs we see wonderful displays of color as different elements have leached into the cave to decorate the walls and ceiling.  Iron is the most prevalent and different hues of red streak the basalt to add a wonderful visual to our venture of discovery.

The floor is smooth now, well, as smooth as a very non-viscous basalt can be as it cools and you will come across many cooling cracks.  These “cracks” in the floor always form parallel to the flow and are commonly referred to as ankle breakers, be careful for they range in size from a few inches to over a foot.  One can often see evidence of other humans in the flashlights that have fallen into these apparently bottomless cracks into the earth.

The air is a bit stale now and we must be approaching our end, or in the case of this lava tube, the beginning. We pass some splash downs, obvious pieces of ceiling that fell as the floor was cooling.  These smooth pieces of rock often have a trailing edge where the lava of the floor has started to pillow over the top, and a foreword edge still rough from where it broke from the ceiling.  

And there it is the end, the section of the tube where the ceiling has almost completely collapsed and a full-grown person will have difficulty in proceeding.    There is no light at the end of this tunnel, only discovery of what the surface of Northern Arizona used to look like.  And if you are prepared, this is when you get out your wintergreen lifesavers, pop into your mouth, use saliva to loosen up the candy and then bite and crunch the treat with your mouth open.  Sparks will fly as a celebratory congratulations to your accomplishment, you have hiked the Lava River Cave.