September 4

1857 Lieutenant Gouverneur Kemble Warren explored the area between Fort Laramie and the Black Hills in 1857. On September 4, he and his party left Fort Laramie for the Black Hills.

1878 In September 1878, Ferdinand V. Hayden and his survey party continued the exploration of the thermal features of Yellowstone. On September 4, they were in the Heart Lake Geyser Basin. The "principal" geyser in the Heart Lake Geyser Basin was Rustic Geyser, named because of a surrounding cordon of logs probably placed by early trappers and coated with a heavy deposit of geyserite.

1885 Department of the Platte Special Order 86 of September 4, 1885 directed Company A, 9th U.S. Infantry and Company I, 21st U.S. Infantry to Evanston to protect both the U.S. Mail and the Chinese laborers from anti-Chinese rioters who were destroying property of the Union Pacific Railroad. Special Order 105, Department of the Platte dated October 20, 1885 named the camp Medicine Butte.