This 3/4-mile long lava tube is located in the Coconino National Forest. A few miles of graded dirt road driving is required, but all vehicles should be able to make the drive. The Forest Service allows you to enter the cave.
Be prepared for 42 deg F (5 deg C) temperatures and bring you own light source (two would be preferable in case one goes out). Inside the cave, the rocks are slick and jumbled.
This lava tube formed approximately 675,000 years ago in a basalt lava flow that erupted from a vent near Hart Prairie located a few miles to the west. Sometime during that flow the surface of the lava flow cooled and hardened forming an insulating cover. Molten lava continued to flow under it. When the eruption ended, the lava continued out the end of the tube leaving an empty void under the solid surface. Typically, lava tubes are sealed on both ends with rock, but in some places the surface has collapsed creating entrances.
The same insulation that kept the lava hot as it flowed through the tube keeps the air inside cool. The temperature fluctuates only slightly throughout the year. Sometimes ice can be found in the cave even on the hottest summer day.
Inside the lava tube are a number of features that are frozen into the solidified rock. There are ripples along some portions of the cave floor from the flowing lava. Stone “icicles” hang from the ceiling caused by a blast of volcanic activity which partially re-liquified the cave roof. There are also “splashdowns,” other rocks that got embedded into the lava. At one point, the lava tube reaches 30 feet high.
Logging requirements:
Send me a note with :
- The text "GCZ5GB Lava River Cave" on the first line
- The names of the geocachers in your group.
- Select one of the features located on the informational sign then go into the cave and find it. Post a picture of the feature you selected. Without a picture describe the feature in the log and give a short explanation on how it was formed.
- Sign the log at the entrance and make a note you are earthcaching.
The above information was compiled from the following sources:
- Lava River Cave Description, http://www.fs.fed.us/r3/coconino/recreation/peaks/lava-river-cave.shtml
- Forest Service Informational Signs
Placement approved by the Coconino National Forest