Polk County is one of the 36 counties in the U.S. state of Oregon. As of the 2020 census, the population was 87,433. The county seat is Dallas. The county is named for James Knox Polk, the 11th president of the United States.

The Provisional Legislature of Oregon was the single-chamber legislative body of the Provisional Government of Oregon. It served the Oregon Country of the Pacific Northwest of North America from 1843 until early 1849 at a time when no country had sovereignty over the region. This democratically elected legislature became the Oregon Territorial Legislature when the territorial authorities arrived after the creation of the Oregon Territory by the United States in 1848. The body was first termed the Legislative Committee and later renamed the House of Representatives. Over the course of its six-year history the legislature passed laws, including taxation and liquor regulation, and created an army to deal with conflicts with Native Americans.