August 30

1873 During the summer of 1873, Captain William A. Jones and party explored northwestern Wyoming and Yellowstone. On August 30, they climbed Mount Sheridan to continue their "inspection of the Yellowstone Lake Basin." Mount Sheridan was named by Captain J. W. Barlow, a military member of the 1871 Hayden Expedition, for General Philip H. Sheridan, who supported the effort to preserve the wonders of the park. It was also known as Brown Mountain, Yellow Mountain and Red Mountain.

1886 Douglas, Wyoming was established in August of 1886 during the selling of land parcels at the end of the month.