Columbia County is a county located in the state of Oregon. As its name suggests, it is located on the Columbia River, north of Multnomah County. The county is fairly small in area (around 650 miles) and population (around 52,000 people). It is considered to be part of the Portland metropolitan area, although its towns are separated from Portland by long sections of rural areas.
Along with long sections along the Columbia River, the county also includes much area in the Oregon Coast Range, which while not very high at this point, can have very rugged terrain due to the high rainfall. Cities along the Columbia River include Scapoose, Saint Helens, and Rainier, while the largest city inland is Vernonia. Like much of Oregon, the area was first settled by Europeans for reasons of resource extraction, mostly timber, and that still remains an important part of the economy, although the economy has diversified, including being a home to bedroom communities for both the Portland area, and the Kelso-Longview, Washington area in Washington. It was also the site of the Trojan Nuclear Power Plant, near Rainier. Compared to most of the Portland area, the area is less diverse (over 90% non-Hispanic white) and politically conservative (most presidential elections turn out to be about 50/50) than the rest of the Portland metro, but it is still not conservative for a white, suburban area, compared to the US as a whole.
Also, as someone who lived in the Portland area for a long time, most Portlanders would talk about places like Scappoose and Rainier as if they were distant hinterland towns, even though they are a half-hour drive from downtown Portland. But for that matter, Portlanders would often talk about anything outside of downtown and core Portland as if it was distant.