that year. The portion of the freeway between Weverton and MD 180 east of Petersville was under construction in 1964 and completed in 1965. MD 180 was assigned to old US 340 from Sandy Hook to west of Jefferson in 1965. Construction on the US 340 freeway east toward Frederick began in 1966. The freeway east to the current Point of Rocks – Jefferson segment of US 15 was completed in 1967; however, the US 15 interchange would not become operational until the new US 15 was completed and the two U.S. highways became concurrent in 1970. US 340's interchanges with I-70 and MD 180 were completed in 1968 and the portion of the freeway from the US 15 interchange east to MD 180 opened in 1969. At that time, MD 180 was extended east over the old Jefferson–Frederick section of US 340. US 340's interchanges with MD 67 in Weverton and Mt. Zion Road near Frederick opened in 1971 and 1972, respectively. Several ramps were added to improve access between US 340 and I-70 in 1997, including a pair of ramps from eastbound I-70 to US 340 and the connection from northbound US 340 to westbound I-70 at US 340's northern terminus. The interchange at US 340's northern terminus was converted from a cloverleaf interchange to a partial cloverleaf interchange with traffic signals in 2004. Sandy Hook Bridge US 340 originally followed Sandy Hook Road south and west from what is now Keep Tryst Road in Sandy Hook and paralleled the Potomac River west to Maryland Heights directly across the river from downtown Harpers Ferry. There, the U.S. highway crossed the river on a converted railroad bridge immediately upstream from the confluence of the Potomac and Shenandoah rivers and downstream from the two railroad bridges—one for CSX's Cumberland Subdivision on the north and the other for the Shenandoah Subdivision—that presently cross the river at the site. After the highway bridge was destroyed in the March 1936 flood, a wooden floor was placed on the Shenandoah Subdivision bridge for that bridge to temporarily serve both rail and automobile traffic. Later in 1936, Maryland and West Virginia acquired the right-of-way of the destroyed toll bridge owned by the Harpers Ferry and Potomac Bridge Company by eminent domain with an aim to build a new bridge at the site. In August 1939, Maryland, West Virginia, and Virginia decided to instead embark on