Interstate 84 (I-84) in the U.S. state of Oregon is a major Interstate Highway that traverses the state from west to east. It is concurrent with U.S. Route 30 (US 30) for most of its length and runs from an interchange with I-5 in Portland to the Idaho state line near Ontario. The highway roughly follows the Columbia River and historic Oregon Trail in northeastern Oregon, and is designated as part of Columbia River Highway No. 2 and all of the Old Oregon Trail Highway No. 6; the entire length is also designated as the Vietnam Veterans Memorial Highway. I-84 intersects several of the state's main north–south roads, including US 97, US 197, I-82, and US 395. The freeway serves as the main east–west route through Portland and Gresham and continues into the Columbia River Gorge National Scenic Area. It passes through the cities of Hood River and The Dalles within the gorge and also serves several state parks and natural monuments. Near Pendleton, it leaves the Columbia River and runs southeasterly across the Blue Mountains via La Grande and Baker City. I-84 crosses the Snake River at Ontario, continuing southeast towards Boise, Idaho. I-84 was established in 1957 and originally carried the designation of Interstate 80N (I-80N) until 1980, when this was changed to I-84 to prevent confusion with the southerly I-80. The earliest sections of the freeway incorporated the existing Banfield Freeway between Portland and Troutdale, opened in 1955, and upgraded other parts of US 30 to Interstate standards. New roads were built through the Columbia River Gorge in the 1960s and across northeastern Oregon in the 1970s. The final section of I-84, near Baker City, was opened to traffic on July 3, 1975. Route description Interstate 84 is the longest freeway in Oregon, at over in length, and is the only Interstate to traverse the state from west to east. The highway connects the Portland metropolitan area to the Columbia River Gorge, the northeastern Columbia Plateau, and part of the Snake River Valley. As a component of the Interstate Highway System, I-84 is also designated as an important national highway under the National Highway System. It is officially named the Vietnam Veterans Memorial Highway and is mostly concurrent with US 30, which also carries part of the Columbia River Highway No. 2 and all of the Old Oregon Trail Highway No. 6 under Oregon's named route system.