more than 100 years ago, a photographer named timothy o'sullivan went into the west to create the most top graphically surveys. now the american art museum has the largest collection of those photographs in an exhibit entitled "framing the west." the survey photographs of timothy o'sullivan. >> reporter: the american west was out there, undisturbed, largely unexplored. and photographer timothy o'sullivan was asked to capture is on film so it could be charted and cataloged for the government back east. and so he headed into america's wilderness. >> it must have an overwhelming and difficult and emotional experience. that's really what we're trying to show with the work. >> reporter: it must have provided some relief for o'sullivan be faced whiff the majesty. he had just spent the last years photographing the civil war. here, he found a pristine landscape free of man's carnage. shoshone falls, reaching higher than the great niagara. the humble ridge. the land had a power. and o'sullivan was the first photographer to not just see it, he clearly felt it. >> the way people respond to the la