Interstate 5 (I-5) is an Interstate Highway on the West Coast of the United States that serves as the region's primary north–south route. It spans 277 miles (446 km) across the state of Washington, from the Oregon state border at Vancouver, through the Puget Sound region, to the Canadian border at Blaine. Within the Seattle metropolitan area, the freeway connects the cities of Tacoma, Seattle, and Everett.

Vancouver is a city on the north bank of the Columbia River in the U.S. state of Washington, located in Clark County. Founded in 1825 and incorporated in 1857, Vancouver had a population of 190,915 as of the 2020 census, making it the fourth-most populous city in Washington state. Vancouver is the seat of government of Clark County and forms part of the Portland-Vancouver metropolitan area, the 25th-largest metropolitan area in the United States. Originally established in 1825 around Fort Vancouver, a fur-trading outpost, the city is located on the Washington–Oregon border along the Columbia River, directly north of Portland, and is considered a suburb of the city along with its surrounding areas.