This reddish, layered
sedimentrary rocks are Pre-Cambrian age, at least 1.1 billion years
old. Within the layers are mud cracks and ripple marks that represent
the action of currents in a shallow water environment, during a time
that preceeded multicellular organisms. One of the more spectacular
views of the Hakatai shale is here at Hance Rapids, where the unit is cut
by lava of an ancient volcanic dike.
Hakatai is also the Havasupai Indian word for the Colorado