How did craters of the moon national park form?
Thousands of years ago the area had active volcanoes. You can still see the ash cones, plus there are many acres of lava flows, where molten rock flowed out over the ground. Where the lava covered the ground completely, then hardened, it looks sort of like the surface of the moon. We camped there, and it was like camping on the moon! The lava rock is two kinds, which have Hawaiian names. What’s called ‘aa’ (AH-ah) is very porous and light, it actually floats on water. The other kind is pahoehoe (pa-hoy-HOY), which flowed like melting ice cream, then hardened, making designs of swirly marks on the surface. There are also caves where lava flowed in a round shape, then it was covered by ash and rock, then the lava eroded away and left a cave. One of the caves has 2-3″ of ice on the floor year round, even when it’s 95 degrees outside. It’s very strange when it’s so hot to climb down only eight or ten feet and suddenly it’s very cold, like walking into a refrigerator.
