- So, what we're known for at Fossil Butte is actually not only the preservation but the diversity and the abundance of fossils that we find here as well.

So, diversity being all sorts of different types of fish, mammals, and turtles, and crocodiles that tell the story of this whole ecosystem that used to be here.

And then we also have the abundance.

There are so many fossils that you can find in this area that it's really some of the best preserved fish fossils in the whole world.

(stimulating country rock music) My name is Amanda Wilson.

I'm a supervisory park ranger here at Fossil Butte National Monument.

And today we're going to be walking up the nature trail and checking out our research quarry.

- And I'm Liz Bargdill, and I'm our geo scientist and the park's intern.

When we get up to the research quarry, I will show you all about the fossils that we're finding up there in the rocks we're looking at, which is actually a mass mortality of a school of fish.

- So we're about 10 miles outside of Kemmerer, Wyoming off Highway 30.

We get about 20,000 visitors each year to Fossil Butte National Monument.

Our elevation here at the monument is at about 7,000 feet at the visitor center.

We are a part of a three lake system.

So Fossil Lake is the lake that we have here.

It was a smallest of those lakes and it has the best preserved fossils from that time period.

About 52 million years ago, this whole area was like a subtropical environment, so basically similar to the Gulf Coast or Florida today.

This whole area was basically teeming with life So there were crocodiles, and turtles, and fish all living in this lake, as well as a diverse ecosystem with palm trees and all sorts of tropical plants located outside the shores of the lake.

- Fossil Lake was an alkaline lake.

Think of it as hard water precipitating out of the water and settling on the bottom, creating the laminated limestones that we have.

We've gotten more understanding, as we get more information through the years.

When they first found these deposits and were describing them, Bradley, with the United States Geological Survey, said, "Oh, these fish can't live here "because you can't have fish living in a lake "that's precipitating limestone.

"They just can't, the water conditions wouldn't be right."

But the lowly coprolite corrected that.

Fossil fish poo, fossil feces, was found in with these fish.

Very delicate.

You can't get that delicate coprolite to wash out 10 miles from shore, settle to the bottom and still be perfectly articulated.

That told them the fish were actually living here in the lake, which then begged the question, how?

Through time, using evidences like volcanic ash beds that in the middle lake are preserved as a case bar alteration near shore, they're clay.

So that's telling you the same ash is preserving differently, and that's an indication with that case bar alteration in the middle lake, that there was salt water at the base of the lake in the center and fresh above that all the way across the lake.

So as fish were living in the fresh, albeit alkaline water up above, and we have salty water down below.

When they died and went to the bottom, you had this barrier for scavenging, barrier for microbes that protected them on the bottom in that saltier water.

- One of the things people come here to see are the incredible fossils that we have here at Fossil Butte.

The best place to do that is actually in our visitor center.

And some of the fossils that you can see in the visitor center are a 13 foot crocodile, or a crocodilian, I should say.

Turtles, we have turtles on display.

A horse, an early horse from the Eocene era and many different kinds of fish.

- The visitors center was built and dedicated in 1990 and no major or a significant additions to the exhibits were done for 20 years.

In 2010, I added this case, four other cases, increased the number of fossils on exhibit from 80 to over 300 fossils on exhibit.

At the same time, some of these other cases in the room we changed out.

So we keep trying to keep things current, keep things up to date as we have the funds in project money.

- So on Fridays and Saturdays during the summer months visitors are able to come up this trail and visit me in the research quarry where they can help participate in gathering research.

So I put a pencil and notebook in their hand and they help me document information about fossils.

So all sorts of information, such as length, side, articulation, orientation, visitors can expect to help in.

Here's we're looking at the layer that I am working on.

The rock that you're seeing right in front of us used to be the bottom of this ancient fossil lake.

So we are looking at about 52 million year old rock and also fossils.

Now the rock that you're looking at is a fine sedimentary rock.

Think of a bottom of a lake; it's very silty and soft.

Now, the fossils that you're seeing in here are slightly hidden, but all of the numbers and boxes that you see right now, these are indicating fossils that we have here on this layer right now.

And every number is a fossil.

So we have actually been working up here in the research quarry for 21 years.

This is the 21st year someone has been up here documenting data on fossils in these layers.

And each of these layers are given a number.

Currently, this very thin layer that we're seeing right now is called the 128 layer and it is paper thin.

And so I'm looking for fossils on and within this 1/8 of an inch fossil-rich layer.

And so when visitors come up and see that process in the research quarry firsthand, they do have a better appreciation of what we have here and why we have them in the visitor center for them to see.

- Yeah, so one of the big challenges we have is how to be relevant for people.

We're a small national monument, so it can be challenging sometimes for people to hear about us when they think of Yellowstone and Grand Tetons.

So it's how to be relevant for people who are traveling through this area who may have never heard of Fossil Butte before, or never thought of stopping here So many national parks and monuments obviously do charge fees, and we are one that does not.

So we are all together in the National Park Service are funded through the Department of the Interior, so our funding comes from a lot of different places and doesn't necessarily have to come from fees.

So we're able to not have an entrance fee here at Fossil Butte.

The summer is definitely our busiest time here where we get the majority of our visitors and we have the most services available.

Those include ranger programs that are available daily that you can come in and request a program with a ranger.

We do different walks and talks so you can learn more about the monument.

We also have our fossil preparation demonstrations that happen during the summer months which actually show you the process of creating a beautifully-displayed fossil and how how we go about doing that.

The fall and spring are more of our shoulder season where we have some limited services but we're still open daily.

In the winter, we have the least amount of services but otherwise we're entirely open for visitors to come here and experience the visitor center and have opportunities like cross country skiing or snowshoeing.

Fossil Butte became a national monument in 1972.

It was established by an Act of Congress.

And basically it was a way to preserve this part of the fossil lake sediments as an area that could be preserved and protected for future generations.

Definitely, the reaction that we get from people who come here is, "This is an amazing place," and they've may have never heard of it before.

They're really surprised to find it right in their backyard.