1. The Oregon State Penitentiary was established on April 23, 1866. It is the oldest prison in Oregon and has been home to many notorious inmates, including serial killer Dayton Leroy Rogers.

2. On April 23, 1889, the Oregon Railway and Navigation Company completed its line between Portland and Seattle. This helped to increase trade and travel between the two cities and contributed to the growth of the Pacific Northwest.

3. On April 23, 1908, a major earthquake struck Oregon, causing damage to buildings and infrastructure throughout the state. The earthquake had a magnitude of 5.5 and was felt as far away as Portland and Salem.

4. Oregon became the first state in the country to establish a bottle bill on April 23, 1971. The bill required a refundable deposit on all beverage containers, creating an incentive for people to recycle.

5. On April 23, 2015, the Portland Timbers soccer team officially opened their new stadium, Providence Park, with a game against the Vancouver Whitecaps. The stadium has been home to the Timbers since their inception in 2011, and has also hosted international soccer matches and other events.