Help from North Sulphur River

[Dcain926]

Hello, we spent the day yesterday at the North Sulphur River.  We needed help identifying some of our finds.  I also wanted to ask if anyone has ever encountered the mineral Pyrite while exploring NSR.  I tried to include pic also

[All Day Rocks]

In my opinion the first, second, third, and fifth picture are suggestively shaped rocks. The fourth picture looks like a very worn mosasaur vertebrae. Sixth and eighth picture look like river rocks. The seventh picture does seem to be pyrite.

[JarrodB]

The fourth pic is a worn split Mosasaur vert. Pyrite is found at NSR.