- The City of SeaTac was incorporated in 1989 and named after the Seattle-Tacoma International Airport, which it surrounds. Native Americans had occupied the region roughly midway between present-day Seattle and Tacoma for millennia before the arrival of the first Euro-American settlers in the mid-1850s. The area is centered on the Highline ridge separating Puget Sound and the valley of the Duwamish and Green rivers…