1) On September 20, 1850, the Oregon Territory was officially established by the United States Congress. The territory encompassed present-day Oregon, Washington, and parts of Montana and Wyoming.

2) In 1873, the Oregon State Agricultural Society held its first annual fair in Salem on September 20. The fair continues to this day and is now known as the Oregon State Fair.

3) On September 20, 1905, the Lewis and Clark Centennial Exposition opened in Portland. The exposition celebrated the 100-year anniversary of the Lewis and Clark expedition and featured exhibits showcasing the history and development of the Pacific Northwest.

4) On September 20, 1975, the Portland Trail Blazers played their first game in the newly built Memorial Coliseum, defeating the Chicago Bulls 111-104. The Trail Blazers went on to win their first and only NBA championship in 1977.

5) In 2013, the Hood River County Board of Commissioners declared September 20 to be "Ted Walker Day" in honor of the local radio host who entertained listeners for over 60 years on KIHR. Walker passed away in 2012 at the age of 91, leaving behind a legacy of community involvement and broadcasting excellence.