1. Statehood Day: May 5, 1889 was a significant day in North Dakota history as it was the day the state became the 39th state of the United States.

2. The Devils Lake Flood: On May 5, 2011, Devils Lake experienced its worst flood in recorded history, causing thousands of residents to evacuate their homes and causing millions of dollars in damages.

3. The Lost Forty: The Lost Forty is a forest in northern Minnesota near the North Dakota border. On May 5, 1957, it was almost destroyed when loggers mistakenly marked it for logging. However, the error was discovered before it was too late, and the land was saved.

4. The Great Plains tornado outbreak: On May 5, 1964, a massive tornado outbreak hit the Great Plains, including North Dakota. The storms caused significant damage and resulted in several deaths.

5. Lewis and Clark expedition: On May 5, 1805, the Lewis and Clark expedition reached what is now North Dakota while traveling up the Missouri River. It was a significant moment in the expedition's journey, as they entered the region where the Mandan and Hidatsa tribes lived.