I've known (and smiled about) this painting ever since I first visited the library, but today I got my first opportunity to take a picture of it (in other words: today was the first time there was no one manning the front desk to make me feel self conscious about snapping a picture).
There is no information about the painting in the music library, so out of curiosity I tried googling the artist's name to see what turned up. Looks like Robert Lindneux was a pretty highly renowned painter who lived from 1871-1970 and specialized in western subjects. He was born in NYC to Swiss parents and studied art and painting in Germany and Paris. In 1889 he saw Buffalo Bill's Wild West show in Paris and immediately fell in love with the idea of the American West. He moved to Billings Montana where he became a trapper, horse wrangler and cowboy in order to more fully immerse himself within the culture and landscape he wanted to paint.
I wish I knew what lookout this painting depicts. I tried looking through online images to see if I could match one with the painting, but have been unsuccessful thusfar. I guess that in a way it's a bit refreshing to realize that Lindneux found and illustrated a unique perspective of the park that cannot easily be duplicated by any one of thousands of travel pics taken by casual visitors over the years.