| 1807-8 | John Colter, first known white man to set
foot in this region. |
| 1827 | Member of Rocky Mountain Fur Co. visited
Yellowstone. |
| 1830 | Jim Bridger, trader and trapper, believed to
have visited area. |
| 1834 | Warren Angus Ferris, fur trader, wrote first
known account of Yellowstone wonders. |
| 1860 | Raynolds Expedition attempted to enter region
but was blocked by snow. |
| 1863 | Capt. W. W. DeLacy discovered Lewis and
Shoshone Lakes and Shoshone and Lower Geyser Basins. |
| 1869 | The Folsom-Cook-Peterson Expedition traversed
region. |
| 1870 | The Washburn-Langford-Doane Expedition
explored Yellowstone country; through its efforts area was later set
aside as park. |
| 1871 | Hayden Survey party made official explorations
and surveys. |
| 1872 | President Grant signed Act of Dedication,
March 1, establishing first national park as such in world. |
| 1878 | Superintendent Norris constructed famous
Norris Road, a wagon road from Mammoth to Lower Basin. |
| 1881 | Photographer F. Jay Haynes first visited
park. |
| 1883 | President Chester A. Arthur visited
park. |
| 1886 | Camp Sheridan established. Park placed under
military regime. |
| 1894 | Congress passed protective act; United States
commissioner appointed. |
| 1903 | Dedication of North Entrance Arch by President
Theodore Roosevelt. |
| 1918 | Complete civilian control of Yellowstone
Park. |
| 1923 | President and Mrs. Harding visited
park. |
| 1927 | President and Mrs. Coolidge visited
park. |
| 1937 | President and Mrs. Roosevelt visited park. |