The Columbia River Highway, later renamed the Historic Columbia River Highway (HCRH), was a technical and civic achievement of its time, successfully mixing ambitious engineering with sensitivity to the magnificent landscape. The Highway has gained national significance because it represents one of the earliest applications of cliff-face road building applied to modern highway construction. It is also the oldest scenic highway in the United States. The Highway's design and execution were the products of two visionaries, Samuel Hill, lawyer, entrepreneur, and good roads' promoter; and Samuel C. Lancaster, engineer and landscape architect. Many citizens provided strong leadership and advocacy for construction of what they called "The King of Roads."
The Historic Columbia River Highway project focused on the rehabilitation of the roadway itself and the repair of contributing landscape features, such as masonry guard walls, dry masonry retaining walls, guard rocks, bridges, viaducts, and tunnels. Engineer and landscape architect Samuel C. Lancaster (1864-1941) artfully created an engineering achievement sympathetic to the natural landscape that made the Columbia River Gorge's idyllic natural setting accessible to tourists without unduly marring its beauty. The HCRH is owned by the Oregon Department of Transportation and was listed in the National Register of Historic Places in 1983. The American Society of Civil Engineers declared the road a National Historic Civil Engineering Landmark in 1984. Associated pedestrian trails are owned by the Oregon Parks and Recreation Department and the USDA Forest Service. The highway runs from Troutdale, just east of Portland, to The Dalles, about 74 miles in total distance. Of this, 55 miles of the roadway are extant; and nearly 40 miles are drivable. At this time, work is now complete on those segments open to motor vehicles and ODOT is currently rehabilitating abandoned segments for non-motorized use as the Historic Columbia River Highway State Trail.
Destruction of the Highway's Hood River Bridge in 1982 sparked a groundswell of support for saving and restoring the HCRH. In 1986, the Columbia River Gorge National Scenic Area Act called for restoring the highway and for creating trails to connect intact and abandoned segments for recreational use. Historic preservation work began in 1986 and is ongoing. The route was designated an All-American Road in 1998.