These are actual bones exposed in the side of this uplifted cliff. Some bones are quite large.
The theory is that many dinosaurs were caught in a flash flood and
the drebris left a pile of bodies and silt and rock that we now see
as the exposed cliff.
Here as a map showing the excavated and reamaining parts of the
cliff. This one complex of bones is still in tact.
These old photos show the site in the very early years after
discovery.
Some of the finer specimens are on display in the visitor center.
Most of the completed skeletons have been placed in museums around
the country.
The landscape aroung the dinosaur cliff shows the river bed of the
Yampa river and the uplifted cliffs and hills.
There are probably more donosaur bones buried in some of these
hills.