Medical doctor and geologist Dr. Ferdinand Vandiveer Hayden selected more than 30 scientists, technical personnel, and artists, including photographer William Henry Jackson and painter Thomas Moran, to join the survey of the Yellowstone region in northwest Wyoming territory. Thomas Moran was an accomplished artist when he joined the survey to capture the natural splendor of the American West in pencil, watercolor, and paint. He spent about 40 days in the Yellowstone area documenting more than 30 different sites. The "benefit and enjoyment" Moran had experienced in Yellowstone was evident in a letter he wrote from Newark, New Jersey, on March 11, to Ferdinand Hayden. In describing his progress on "The Grand Canyon of the Yellowstone," he explained how moved he had been by his visit and how the scenery challenged him as an artist. It was not enough for Moran that his painting be beautiful, he felt it must also accurately depict nature, if not an exact scene. While many of his friends thought the painting a "great success," Moran believed that it would not be finished until the scientific eye of Frederick Hayden had gazed upon it. (Contains 5 notes.)