Yellowstone National Park, Wyoming, Idaho, Montana, United States

The expedition spent about a month exploring the region, collecting specimens, and naming sites of interest. A Montana writer and lawyer named Cornelius Hedges, who had been a member of the Washburn expedition, proposed that the region should be set aside and protected as a National Park; he wrote a number of detailed articles about his observations for the Helena Herald newspaper between 1870 and 1871. Hedges essentially restated comments made in October 1865 by acting Montana Territorial Governor Thomas Francis Meagher, who had previously commented that the region should be protected. Others made similar suggestions. In an 1871 letter from Jay Cooke to Ferdinand Hayden, Cooke wrote that his friend, Congressman William D. Kelley had also suggested "Congress pass a bill reserving the Great Geyser Basin as a public park forever".
• Park creation
In 1871, eleven years after his failed first effort, F.V. Hayden was finally able to make another attempt to explore the region. With government sponsorship, Hayden returned to Yellowstone region with a second, larger expedition, the Hayden Geological Survey of 1871. He compiled a comprehensive report on Yellowstone, which included large-format photographs by William Henry Jackson, as well as paintings by Thomas Moran. His report helped to convince the U.S. Congress to withdraw this region from public auction. On March 1, 1872, President Ulysses S. Grant signed The Act of Dedication law that created Yellowstone National Park.
Ferdinand V. Hayden, while not the only person to have thought of creating a park in the Yellowstone region, was the park's first and most enthusiastic advocate. He believed in “setting aside the area as a pleasure ground for the benefit and enjoyment of the people” and warned that there were those who would come and “make merchandise of these beautiful specimens”. Worrying the area could face the same fate as Niagara Falls, he concluded the site should “be as free as the air or Water.” In his report to the Committee on Public Lands, he concluded that if the bill failed to become law, “the vandals who are now waiting to enter into this wonder-land, will in a single season despoil, beyond recovery, these remarkable curiosities, which have requited all the cunning skill of nature thousands of years to prepare”. Hayden and his 1871 party recognized that Yellowstone was a priceless treasure, which would become rarer with time. He wished for others to see and experience it as well. Eventually the railroads and, some time after that, the automobile would make that possible. The Park was not set aside strictly for ecological purposes, however the designation “pleasure ground” was not an invitation to create an amusement park. Hayden imagined something akin to the scenic resorts and baths in England, Germany and Switzerland.