By the time Hayden's expedition left the Yellowstone region, its members had accumulated many notes, sketches, photographs, specimens, and scientific data. Hayden immediately began preparing his findings for a published report. Hayden's report was a valuable resource; however, the other materials he put on display for congressmen to view left a greater impression. Many members of Congress had not seen Yellowstone. The specimens, along with Jackson's photographs and Moran's sketches, were proof that the stories about the region's wild formations were indeed true. Hayden also wrote an article for Scribner's magazine and illustrated it with wood engravings like this one by Moran. His illustrations were now more accurate and convincing than his earlier Scribner's pictures had been, as he had now seen the Yellowstone region first-hand.

Illustration: Thomas Moran, The Grand Canyon and Lower Falls of the Yellowstone, wood engraving, Scribner's Monthly, February. 1872. Buffalo Bill Historical Center.