GUEST: I brought a photograph from William Henry Jackson.

It's of the Animas River and the Denver and Rio Grande coming from Durango to Silverton, Colorado.

I acquired it at an auction probably 15 to 20 years ago.

I'm kind of a train buff... APPRAISER: Mm-hmm.

GUEST: ...of Colorado railroads.

APPRAISER: Okay.

GUEST: And I liked the train.

And then when I saw it was a William Henry Jackson, that just made it that much better.

APPRAISER: This is a beautiful photograph.

It is, as you said, by William Henry Jackson.

The title is Canon of the Rio Las Animas: The Needle Mountains.

It's a mammoth plate albumen print, so that refers to the size of the photograph.

A mammoth plate print was made from a glass negative in this exact size, which is pretty extraordinary.

William Henry Jackson is really known as a photographer who worked in Colorado, so local to where we are today.

He's actually East-Coast-born, he's from New York state.

He served in the Civil War, and then he headed west.

He worked as a bullwhacker in Nebraska.

So he really had kind of this rugged, hands-on experience in what was then really the West.

He then opened a photo studio in Nebraska.

He was taking portraits, decided that wasn't really working well for him, moved to Colorado.

He was relatively quickly hired by Ferdinand Hayden, who was doing a geological survey of the Western territories and states.

And that was in 1870, and he was hired to document it as a photographer.

Hayden really recognized how important photography would be to his mission, which was to record the geology of the area.

He headed down the Yellowstone River, and those images were published relatively quickly and really caused a pretty major sensation, because people had never seen the elements of the Western landscape that we're all familiar with today, like the geysers and humongous waterfalls.

I mean, this was brand-new.

Just two years later, in 1872, that region became our first national park, Yellowstone National Park.

The photograph is circa 1882, after he had completed his work for the geological survey and had begun opening his own business in Denver.

At this point, Jackson was commissioned by a lot of railroad companies to document the railroads, which were expanding into this region.

When you think about it, he's lugging enormous glass plates, all of his chemicals, a tent to develop the plates, which needed to be done quickly.

So he was really working very hard to produce these stunning photographs.

GUEST: Yeah.

APPRAISER: How much did you pay for this?

GUEST: I paid $250 for it.

APPRAISER: Okay.

Do you have a sense of how much it might be worth today?

GUEST: My guess would be $3,000-plus.

APPRAISER: Okay.

GUEST: I don't really know.

APPRAISER: My estimate at auction would be $6,000 to $9,000 for this print.

GUEST: Okay.

Yeah, thanks.

APPRAISER: (chuckles) Yeah.

GUEST: That's really neat.