Who would have thought that on the heels of National Park Week 2020 comes Cave Week!  So today we lace up our hiking boots and head underground to explore and talk about the caves of the National Parks.  Mammoth Cave may be the largest, Carlsbad may be the most well-known, but there are so many others across the country to explore, each with their own unique features and tours.  As a matter of fact, there are over 4,700 caves that the National Park system manages, with at least four of these that extend for more than 135 miles.  Let’s go spelunking…

Solution Caves in Parks

These caves are formed by the dissolving of the rock along and adjacent to joints (fractures), faults, and layers in the rock. The processes involved are both chemical corrosion and physical erosion. Solution caves are most often found in rock types such as limestone, marble, and gypsum and are associated with karst landscapes.

The following is a partial list of National Park Service units that include solution caves:

Lava Tubes in Parks

When fluid, molten lava flows out of the ground, it works its way downhill. Soon the surface of this lava stream cools and hardens into a crust. Although the outer crust is hard, the lava inside is still molten, and continues to flow downhill. Once the molten lava has passed through, it leaves an empty tunnel called a lava cave, or more commonly, a lava tube.

The following is a partial list of National Park Service units that include lava tubes: