- Local history buffs call Clark County the “Cradle of Pacific Northwest History,” reflecting the importance of the 628-square-mile southwestern Washington county as the scene of key historical developments. Here the Lewis and Clark expedition arrived in 1805, the British Hudson’s Bay Company established Fort Vancouver in 1825, and the town of Vancouver was incorporated in 1857. The county’s location first made it an entrepôt (trading center), then an agricultural area. The region developed in agriculture, lumber, and fishing, and later in shipbuilding and aluminum. In recent times, energy from hydroelectric projects on the Lewis and Columbia rivers has fueled development as a manufacturing center.