West Side Highway was a census-designated place (CDP) in Cowlitz County, Washington, named after a state highway (SR 411) running north–south between Longview and Castle Rock.

[3] Prior to the 2020 census, the CDP was split into two new CDPs, Beacon Hill and Lexington.

As of the census[2] of 2000, there were 4,565 people, 1,635 households, and 1,291 families residing in the CDP.

The racial makeup of the CDP was 94.22% White, 1.23% Native American, 1.12% Asian, 0.26% African American, 0% Pacific Islander, 0.81% from other races, and 2.37% from two or more races.

16.8% of all households were made up of individuals, and 6.8% had someone living alone who was 65 years of age or older.