Rockcreek is a census-designated place in Washington County, Oregon, north of U.S. Highway 26. It is named for the Rock Creek neighborhood in the area. As of the 2000 census, the CDP population was 9,404. Rockcreek apartments for rent comparison page shows most up to date rent information on Rockcreek apartments and houses. Rent information is obtained from multiple rental sources but we cannot guarantee their accuracy.