Ferdinand Vandeveer Hayden (September 7, 1829 – December 22, 1887) was an American geologist noted for his pioneering surveying expeditions of the Rocky Mountains in the late 19th century.

Being of independent mind Hayden ended his commission with Hall, and with the encouragement of S. F. Baird, and a partial sponsorship from the Smithsonian Institution, he spent the remainder of the 1850s on various exploring and collecting expeditions in the northern Missouri River areas.

After the American Civil War Hayden led geographic and geologic surveys of the Nebraska and Western Territories for the United States Government.

In 1870 he received a $25,000 governmental grant to lead a 20-man expedition to South Pass, Fort Bridger, Henry's Fork, and back to Cheyenne.

[7] In 1871, Hayden led America's first federally funded geological survey into the Yellowstone region of northwestern Wyoming, given directions by President Ulysses S. Grant's Secretary of Interior Columbus Delano.

[8] The survey consisted of some 50 men which included notables such as painter Thomas Moran and famous frontier/Civil War photographer William Henry Jackson.

The following year, Hayden and his work, Preliminary Report of the United States Geological Survey of Montana and Portions of Adjacent Territories; Being a Fifth Annual Report of Progress[9] was instrumental in convincing Congress to establish Yellowstone as the first U.S. National Park, aided by Jackson's stunning large-format photographs and Moran's dramatic paintings.

From his twelve years of labor and annual survey journeys there resulted a most valuable series of volumes in all branches of natural history and economic science; and he issued in 1877 his Geological and Geographical Atlas of Colorado.

As a result of Hayden's extensive geological work, he uncovered numerous dinosaur fossils which he brought back east with him for further scientific study.

[14] In 2018, Native American leaders have called for it to be renamed, because he "advocated for the extermination of tribal people who refused to comply with federal dictates".