1. Oregon became a state on May 17, 1859. At the time, it was the 33rd state to join the Union.

2. May 17, 2004, was a historic day for same-sex couples in Oregon. That day, Multnomah County began issuing marriage licenses to same-sex couples, making it the first county in the state to do so. While the marriages were eventually nullified by the Oregon Supreme Court, it paved the way for a legal battle over same-sex marriage that eventually resulted in its legalization in 2014.

3. May 17, 1973, marked the first official opening of the MAX light rail system in Portland, Oregon. The initial line ran from downtown Portland to Gresham, a distance of about 15 miles. Today, the MAX system consists of five lines that cover more than 60 miles of track.

4. On May 17, 1900, Oregon's famous Pendleton Round-Up rodeo had its first event. The rodeo has been held every year since on the second full week in September.

5. In 1986, May 17 was declared "St. Brendan's Day" by the Oregon Legislature. The day honors the Irish monk who, according to legend, sailed to America centuries before Christopher Columbus. The Irish Cultural Society of Oregon holds an annual St. Brendan's Day celebration in honor of the monk.