May 16

1878 Camp Stambaugh near South Pass was abandoned on May 16, 1878, in accordance with Department of the Platte General Order 4.

1879 La Plata Post Office in Carbon County was established on May 16, 1879.

1879 Goodwin's Ranch Post Office in Laramie County was established on May 16, 1879 with Oliver P. Goodwin as postmaster. It was located near Horse Creek. Earlier, the location was known as Fagan's Ranch or Horse Creek Ranch, which was the second station on the Cheyenne and Black Hills Stage Route.

1890 On May 16, 1890, Weston County was organized.