1. St. Patrick's Day celebrations in Portland date back to the mid-1800s, with the first recorded celebration taking place in 1849. Irish immigrants who came to Oregon in search of gold or to work on the railroads brought with them their traditions of celebrating St. Patrick's Day.

2. In 1905, the Portland Rose Society held its first rose show on March 17, which coincided with St. Patrick's Day. The show was a success and became an important event in the city's annual Rose Festival.

3. In 1922, a new law in Oregon made it illegal to sell alcohol on St. Patrick's Day. The law was part of a larger movement to ban alcohol sales in the state, which lasted until Prohibition was repealed in 1933.

4. The Tillamook Burn was a series of devastating wildfires that swept through Oregon in the early 1900s. The largest fire, which started on March 16, 1933, continued to burn on St. Patrick's Day, forcing hundreds of people to evacuate their homes.

5. On March 17, 1966, the Oregon State Highway Division dedicated the new Interstate 5 bridge over the Columbia River. The bridge, which connects Portland, Oregon to Vancouver, Washington, is known today as the Marquam Bridge and carries over 135,000 vehicles each day.