Pluto's Cave

Status: Open

This area is Open


Pluto's Cave is one of the main feeder tubes which carried most of the lava into the Shasta Valley.  The small domes of lava in the vicinity of the main entrance are called schollendomes and were formed when the tube was filed with lava to the point where fluid pressure caused an actual inflation of the flow, causing it to rise up, bulge and form the small domes.

The diameter of this cave is exceptionally large; larger than many of the major caves in the Hawaiian Islands.  Multiple lava flows are visible in the walls of Pluto's Cave and can be identified by seeing the layered basalt which is fine grained at the base, and coarse textured and full of gas bubbles (vesicles) near the top.  The skylights along the length of the cave were formed as the lava cooled and collapsed.