US 20 starts at an intersection with US 101 in Newport, and travels eastward over the Central Oregon Coast Range to Corvallis. In Corvallis, it intersects Oregon Route 99W and briefly travels concurrent with OR 34 before proceeding northeast to Albany. From Albany, US 20 briefly travels concurrent with OR 99E before turning east through Lebanon and Sweet Home and entering the Cascade Mountains. It intersects OR 126 west of Santiam Pass and the two routes travel concurrent through Sisters. US 20 then continues eastward and southward to Bend, where it travels roughly parallel to US 97 for about before turning east through Brothers and Riley. At Riley, US 20 travels concurrent with US 395 through Hines and Burns to about northeast of Burns. From Burns, US 20 continues east through Juntura and Vale. In Vale, US 20 travels concurrent with US 26, and the two highways continue east to Cairo Junction, south of Ontario, and turn south, where they then also travel concurrently with OR 201 to Nyssa. Eastward from Nyssa, US 20/US 26 continue to the Idaho state line. The route throughout most of Oregon serves as an important link between Central and Southern Oregon and far Northern California to Boise, Idaho.
Special routes
US 20 has 2 business routes in Oregon: one in Toledo, and one in Bend.
Future
Construction on a portion of US 20 between Newport and Corvallis, specifically, from just west of Chitwood to Eddyville, is being done to straighten and remove nearly from the route. Nearly all of the new highway was opened in October 2016, with just a small portion of new road at the west end, and further environmental remediation, to be completed in 2017. The project made it easier for larger vehicles to travel, provided greater passing opportunities, and upgraded the highway to modern safety standards. Construction began in 2005, but was halted in 2007 because of excessive unexpected landslides. The project recommenced in May 2008 with a better plan for stabilizing these landslide locations. The final construction was expected to be completed in 2011, but continuing earth movement at four of the bridge sites delayed the project again. The Oregon Department of Transportation and the contractor were in a dispute over liability and money, a settlement was agreed upon, and the original design-build contract was rescinded. ODOT assumed control of the project and began completing the project in five phases, replacing the troublesome bridges with earth fill. Because of the previous delays, completion of the project was postponed until fall of 2016 for traffic on the road section, and late summer of 2017 for habitat improvement. The project is now estimated to cost $365.7 million.
Oregon highway designations
The Oregon section of US 20 consists of the following highways numbered using ODOT's internal numbering system, from west to east:
