8.
The boulders of mixed colors topping the pedestals of Zuñi sandstone are the Basal Conglomerate of the Dakota formation. This involved erosion and reworking of the old surface (Zuñi) plus the deposition of new materials. Thus some of the light colored particles in the Dakota are Zuñi sandstone.
The steps cut in the rock were constructed by the National Park Service. They are not the work of prehistoric Indians.