Cowlitz County is County located in the US State of Washington. The county seat is Kelso and its largest city isLongview. The county was formed on April 21, 1854. Its name derives from the anglicized version of the Cowlitz Indian term, Cow-e-liske, meaning either “river of shifting sands” or “capturing the medicine spirit.”
Prior to the Europeans' arrival to the area, it was inhabited by numerous Native American tribes, with the Cowlitz tribe being the largest. They were drawn to the region by the abundance of Salmon. The Cowlitz are considered to be the first regional inhabitants to engage in commerce as they traded extensively with other tribes in Western and Eastern washington The Cowlitz Indian population declined significantly from the 1829-1830 smallpox outbreak.
European explorers discovered and began navigating the Columbia River in 1792 as British Lieutenant W. R. Broughton sailed up the river to and past present day Cowlitz County. Then on November 5, 1805, Lewis and County camped at that mouth of the Kalama River under orders from President Thomas Jefferson. Over the following days, they would reach the present sites of Kelso and Longview.
By the 1820s, the Hudson Bay Company had established a lucrative fur trade in the region. Furs were shipped down the Cowlitz River to the Columbia where they were loaded and shipped around the world. Trade declined significantly in the late 1830s as over-hunting and fashions had changed.
Cowlitz County is part of the Puget Sound – Willamette Depression, a geologic formation extending south from the Puget Sound to the Willamette Valleyt in Oregon.. Nestled up against the Cascade Mountains, many of the county’s major rivers originate in this range. These rivers include the Columbia, Cowlitz, , Kalama, Lewis and Toutle.
Cowlitz County is the 28th largest out of 39 counties in Washington State.