In 1921, he was hired to paint Glacier Lake, in Glacier National Park by the Great Northern Railroad Company as part of their ‘See America First’ campaign. He produced more than 20 paintings, among the artist's last works, that now poignantly remind viewers of the vast disappearing glaciers. Eaton tended to approach this mountain scenery from an oblique vantage point; he liked to capture small episodes, showing mountaintops nearly obscured by dramatically attenuated screens of fir trees.