Historic Columbia River Highway partially coincident with Historic Columbia River Highway State Trail
The Historic Columbia River Highway is an approximately 75-mile-long (121 km) scenic highway in the U.S. state of Oregon between Troutdale and The Dalles, built through the Columbia River Gorge between 1913 and 1922. As the first planned scenic roadway in the United States, it has been recognized in numerous ways, including being listed on the National Register of Historic Places, being designated as a National Historic Landmark by the U.S. Secretary of the Interior, being designated as a National Historic Civil Engineering Landmark by the American Society of Civil Engineers, and being considered a "destination unto itself" as an All-American Road by the U.S. Secretary of Transportation. The historic roadway was bypassed by the present Columbia River Highway No. 2 (Interstate 84) from the 1930s to the 1950s, leaving behind the old two-lane road. The road is now mostly owned and maintained by the state through the Oregon Department of Transportation as the Historic Columbia River Highway No. 100 (still partially marked as U.S. Route 30; see Oregon highways and routes) or the Oregon Parks and Recreation Department as the Historic Columbia River Highway State Trail.
The original highway was promoted by lawyer and entrepreneur Sam Hill and engineer Samuel C. Lancaster, to be modeled after the great scenic roads of Europe.  From the very beginning, the roadway was envisioned not just as means of traveling by the then popular Model T, but designed with an elegance that took full advantage of all the natural beauty along the route.
When the United States highway system was officially established in 1926, the highway became the part of U.S. Route 30. Since then, modern Interstate 84 has been built parallel to the highway between Portland and The Dalles, replacing it as the main travel route and resulting in the loss of some of the original sections of road.Modern highways, including I-84, and other developments have resulted in the abandonment of major sections of the historic original highway. In the interest of tourism and historical preservation, seventy-four miles of the original road—from Troutdale to The Dalles—have been established as the Historic Columbia River Highway (HCRH). Forty miles of the route are open to motor vehicles:The 24 westernmost miles starting in Troutdale (at the eastern edge of urban Portland) provide access to dozens of hiking trails, Crown Point Vista House, and numerous waterfalls such as Multnomah Falls. This section forms a loop with the Mount Hood Scenic Byway.
The 16 easternmost miles ending in The Dalles.The remaining portions of the HCRH designated for non-motorized use are now known as the Historic Columbia River Highway State Trail. These are being developed as money becomes available. Roughly seven miles between Hood River and Mosier have been open to non-motorized traffic since 2000, passing through the historic Mosier Tunnels.Once restoration is complete, the highway will serve as a scenic and alternative bicycle route for I-84 and US 30 between The Dalles and Portland. Currently, cyclists wishing to travel between these two towns must ride on the shoulders of I-84 for much of the distance, or the much more dangerous and narrow State Route 14 on the Washington side of the river.
The Columbia River Highway is the nation's oldest scenic highway. In 1984 it was recognized as a National Historic Civil Engineering Landmark by the American Society of Civil Engineers. In 2000 it was designated a National Historic Landmark by the National Park Service as "an outstanding example of modern highway development".
The Columbia River Highway Historic District was listed on the National Register of Historic Places in 1983.  It includes 38 contributing structures on 529 acres (2.14 km2).
partially overlapping with partially intersecting with partially sharing with partially matching with partially aligning with