1. On October 12, 1870, the U.S. Census Bureau reported that Oregon's population had reached 90,923, an increase of nearly 30,000 people since the previous census in 1860. This growth was spurred by the influx of settlers brought by the Oregon Trail and the completion of the transcontinental railroad.

2. On October 12, 1935, the Bonneville Dam on the Columbia River was dedicated by President Franklin D. Roosevelt. The dam, which spans the border between Oregon and Washington, was built as part of the New Deal to provide hydroelectric power and irrigation to the region.

3. In 1964, Oregon became the first state to create a statewide bottle bill, which required a deposit on all beverage containers in order to encourage recycling. The bill was passed on October 12, and was later expanded to include other types of containers such as aluminum cans and plastic bottles.

4. On October 12, 1999, the Oregon Supreme Court ruled that the state's death penalty was unconstitutional because it was applied arbitrarily and without a clear set of standards. The ruling was later overturned by a ballot measure in 2000, allowing the death penalty to be reinstated.

5. In 2019, the National Park Service announced that Crater Lake National Park in southern Oregon had officially become a "dark sky park," meaning that it had been designated as an area with minimal light pollution to promote stargazing and other nighttime activities. The park's designation coincided with International Dark Sky Week, which takes place in October each year.