U.S. Route 50 (US 50) is a major east–west route of the U.S. Highway system, stretching just over 3,000 miles (4,800 km) from Ocean City, Maryland, on the Atlantic Ocean, to West Sacramento, California, nearly to the Pacific Ocean. In the District of Columbia, US 50 passes between Arlington County, Virginia, and Prince George's County, Maryland, predominantly along surface streets, including a part of Constitution Avenue along the National Mall.