Fort Yellowstone was a U.S. Army fort established in 1891 at Mammoth Hot Springs in Yellowstone National Park. Yellowstone was designated in 1872 but the Interior Department was unable to effectively manage the park. Administration was transferred to the War Department in August 1886 and General Philip Sheridan sent a company of cavalry to Mammoth Hot Springs to build a cavalry post. The army originally called the post Camp Sheridan in honor of General Sheridan but the name was changed to Fort Yellowstone in 1891 when construction of the permanent fort commenced. The army administered the park until 1918 when it was transferred to the newly created National Park Service. The facilities of Fort Yellowstone now comprise the Yellowstone National Park headquarters, the Horace Albright Visitor