1. Oregon's 33rd governor, Frank W. Benson, was inaugurated on December 5, 1910. Benson served as governor during a time of great change in Oregon, overseeing the construction of new highways and bridges, the creation of a state park system, and the establishment of the Oregon State Police.

2. In 1961, the city of Portland experienced one of its worst floods in history on December 5th. Heavy rain caused the Willamette River to rise more than 24 feet, flooding downtown Portland and many of its surrounding neighborhoods. The flood caused widespread damage and resulted in more than $20 million in property damage.

3. On December 5, 1984, the state of Oregon filed a lawsuit against the U.S. Environmental Protection Agency (EPA) over its decision to rollback Clean Air Act regulations. The lawsuit argued that the EPA's decision would have a negative impact on Oregon's air quality and public health.

4. In 2007, December 5th was declared "Pearl Harbor Remembrance Day" in Oregon. The day commemorates the attack on Pearl Harbor by Japanese forces on December 7, 1941, and honors the sacrifices of the men and women who served in World War II.

5. December 5th is also celebrated as "Repeal Day" in Oregon, marking the end of Prohibition in the state in 1933. On this day, Oregonians celebrate their right to consume alcohol legally and reflect on the impact of Prohibition on their state's history.