1. On July 31, 1854, the first steamboat traveled up the Skagit River in Washington, opening up trade and transportation to the region.

2. In 1910, on July 31, the town of Roslyn was hit by a massive forest fire that destroyed thousands of acres of timber and claimed the lives of more than 30 people. The town was rebuilt in the following years, and today it is a popular destination for tourists.

3. July 31, 1939 marks the date when the world's first successful jet aircraft, built by a German engineer named Hans von Ohain, made its maiden flight. Von Ohain moved to the United States after World War II and worked as a professor at the University of Washington.

4. In 1961, on July 31, Boeing announced that it would build a new assembly plant in Everett, Washington, to manufacture its new 747 jumbo jet. The plant, which is now the largest building in the world by volume, has been a major employer in the region for decades.

5. On July 31, 1997, the city of Seattle unveiled the Experience Music Project (now the Museum of Pop Culture), a museum dedicated to the history and culture of popular music. The museum, designed by architect Frank Gehry, features interactive exhibits, multimedia displays, and a vast collection of music artifacts.