Fort Yellowstone

  When Yellowstone National Park was created, on March 1, 1872, it was the first national park in the world. National parks were a new concept and when mountain men and fur trappers first started telling stories about this incredible place of boiling mud pits, geysers and hot springs, no one believed them because it sounded too incredible to be true. The first known person to start talking about Yellowstone's geothermal features was John Colter in 1860. A few people, after hearing his stories about smoke spewing out of the ground began calling the place
 "Colter's Hell," in jest.
  The man that really led the effort to have Yellowstone set aside as the world's first national park was Ferdinand Hayden. He had several unsuccessful attempts before finally succeeding in 1872, when President Ulysses Grant signed the bill creating Yellowstone National P:ark after it was approved by Congress. 
  When Yellowstone National Park was created, the National Park Service did not exist yet, it would be another 19 years before the Park Service was created. Shortly after the park was created, Nathaniel Langford was appointed as Park Superintendent, but he had little money with which to operate and very limited legal authority to deal with poachers, miners, squatters, etc. Yellowstone was basically a park in name only because people were still claiming plots of land to homestead, still cutting timber, still prospecting for gold or other minerals, still grazing cattle within park boundaries and railroad magnates wanted to build railroad lines through the park. The latter situation is most likely what led to administration of the park being turned over to the United States Cavalry in 1886. The Cavalry built Fort Yellowstone in the northern part of the park, in Wyoming, but about 2 miles from the Montana border.  The fort was built adjacent to Mammoth Hot Springs, which is a huge set of hot springs, which are fed by the Norris Geyser Basin through a subterranean fault. These hot springs flow over travertine terraces and into the Boiling River, which, in turn, flows into the Yellowstone River. The buildings of Fort Yellowstone were constructed out of locally quarried sandstone. Almost immediately after the U.S. Cavalry assumed control of the fledgling national park, the 
commanding officers set up backcountry foot and horse patrols, wildlife management and protection and began to vigorously protect the national features of the park that had so inspired visitors to the area. 
In 1891, the National Park Service(NPS), was created by the federal government and they still regard backcountry foot and horse patrols, wildlife protection and management and resource protection, duties that were established by the U.S. Cavalry in 1886, as their primary responsibilities. The Mammoth Hot Springs area, which encompasses Fort Yellowstone, is still the administrative headquarters for Yellowstone National Park.