A park ranger walking through a petrified forest stumbled upon hundreds of prehistoric fossils.

Greg Francek, a ranger naturalist with California's East Bay Municipal Utility District (EBMUD), made the incredible discovery last July.

According to a statement from the EBUMD, Francek found a mastodon skull and a 400-pound monster salmon remains.

The mastodon was from about 10 million years ago.

Francek said he was near the watershed when he noticed what looked like wood, but it was smooth like stone, sticking out of the ground.

"I happened upon a petrified tree, and this tree was partially encased in the burial sediments, and because one end was exposed, I could actually see the tree rings inside," Francek said in a voice recording that EBUMD included with the statement.

According to SF Gate, the tusks of the prehistoric elephant took 130 hours to dig out.

It also took eight people to load them onto a truck because they were so big.

Researchers at California State University, Chico, are now studying the fossils.