Thomas Moran's Castle Rock, Green River, Wyoming depicts a region that played a vital role in westward expansion. The area, which Moran painted repeatedly for more than 40 years, served as a rendezvous for trappers and traders in the early 19th century and witnessed the arrival of the Union Pacific Railroad in 1868. Responding to a longstanding national nostalgia for the untrammeled frontier, Moran effaced signs of settlement and civilization. He also enveloped the tower-like landmark and surrounding landscape in a poetic, atmospheric haze, suggesting both a physical and temporal distance from the viewer.
Moran's western landscapes were so popular among forgers that he "signed" them with a thumbprint- visible at the lower right-to deter unscrupulous reproduction of his paintings.
