1. The Washington State Capitol was dedicated on October 1, 1928. The building, located in Olympia, was designed by architect Joseph Wohleb and features a dome modeled after the dome of the U.S. Capitol building in Washington, D.C.

2. On October 1, 1982, the Pacific Science Center in Seattle opened its first permanent exhibit, called "Dinosaurs: A Journey Through Time." The exhibit features life-size models of dinosaurs, interactive displays, and educational materials about the prehistoric creatures.

3. The Seattle Great Wheel, a 175-foot-tall Ferris wheel located on the waterfront, opened to the public on October 1, 2012. The attraction offers a panoramic view of the city and the Puget Sound, and has become a popular tourist destination.

4. October 1, 1979 marked the opening of Safeco Field, the home stadium of the Seattle Mariners baseball team. The stadium, which has a retractable roof, has hosted several major league baseball games, as well as concerts and other events.

5. The Pomeroy Farm in Yacolt, Washington was designated a historic site by the National Register of Historic Places on October 1, 1974. The farm, which has been in operation since the 1800s, features several preserved buildings and is now used for educational programs and events.