October 30

1889 Chicago, Burlington and Quincy Railroad entered Wyoming.

1900 Cowley Post Office was established on October 30, 1900 with William W. Graham as its first postmaster.

1951 The United States Congress approved the Yellowstone River Compact was entered into by the states of Montana, North Dakota and Wyoming regarding the waters of the Yellowstone River.

1984 The Wyoming Wilderness Act of 1984 became law.