State Route 704 (known as SR 704 or the Cross-Base Highway) is a state highway located entirely in Pierce County, Washington, United States. It is intended to provide access between Interstate 5 (I-5) and SR 7 by passing through a portion of Joint Base Lewis–McChord, a major U.S. military installation. The designated route comprises a short, 0.6-mile (0.97 km) section near SR 7 in Spanaway. The full 6-mile (9.7 km) highway is estimated to cost $480 million to construct, but remains unfunded.