1. On April 26, 1855, the Treaty of Neah Bay was signed between the United States government and the Makah Indian Tribe in Washington. This treaty recognized the tribe's sovereignty and designated a reservation for them. The Makah Reservation is the only Native American reservation in the state of Washington and is located on the Olympic Peninsula.

2. On April 26, 1924, the Oregon State University Beavers played their first-ever baseball game at Bell Field in Corvallis, defeating the Willamette University Bearcats by a score of 22-0. OSU went on to win the Pacific Coast Conference championship that year.

3. On April 26, 1945, the Oregon State Legislature became the first in the nation to pass a state-wide law requiring forestry practices to take into account the protection of wildlife and water resources. This law was known as the "Oregon Forest Practices Act."

4. On April 26, 1969, the Portland Trail Blazers were founded as an expansion team in the National Basketball Association (NBA). The team's first head coach was Rolland Todd and their first home game was played at Memorial Coliseum on October 16, 1970.

5. On April 26, 1986, the Chernobyl disaster occurred in Ukraine, which resulted in the release of radioactive material into the atmosphere. The impact of the disaster was felt worldwide, including in Oregon where elevated levels of radiation were detected in some areas. The Oregon State Health Division issued an advisory cautioning pregnant women and children to avoid drinking milk or eating fresh vegetables until the situation was resolved.