The rocks in the background are sedimentary rocks perhaps a billion years or older. They are the remains of layers that accumulated at the bottom of an ancient shallow sea, crushed and shoved to the surface 40 million years ago when the Rockies were formed. They hold some of the most ancient fossils on Earth, like the remains of some of the earliest bacterial organisms that inhabited our planet.
Clay is a mix of liquid and solid, the product of crush and flow, ancient, epochal, yet fresh as the shape it takes when your hands form it. It's a product of geological processes, a mirror to the history of Earth, yet it takes the shape that one of the planet's most recent creatures imposes upon it.