Significance: One of two nearly identical reinforced-concrete girder trestles on the Historic Columbia River Highway and one of four extant structures on the route that have a distinctive cap and arch concrete More
Significance: One of four tunnels on the Historic Columbia River Highway. Survey number: HAER OR-36-L Building/structure dates: 1914 Initial Construction Building/structure dates: 1948 Subsequent Work Build More
Significance: Rush's Mill Bridge is one of a small number of composite cast- and wrought-iron bridges yet remaining in the U.S. It is also one of the few existing examples employing the Howe-truss form in whic More
Significance: Rush's Mill Bridge is one of a small number of composite cast- and wrought-iron bridges yet remaining in the U.S. It is also one of the few existing examples employing the Howe-truss form in whic More
Significance: Rush's Mill Bridge is one of a small number of composite cast- and wrought-iron bridges yet remaining in the U.S. It is also one of the few existing examples employing the Howe-truss form in whic More
Significance: Rush's Mill Bridge is one of a small number of composite cast- and wrought-iron bridges yet remaining in the U.S. It is also one of the few existing examples employing the Howe-truss form in whic More
Significance: Rush's Mill Bridge is one of a small number of composite cast- and wrought-iron bridges yet remaining in the U.S. It is also one of the few existing examples employing the Howe-truss form in whic More
Significance: Rush's Mill Bridge is one of a small number of composite cast- and wrought-iron bridges yet remaining in the U.S. It is also one of the few existing examples employing the Howe-truss form in whic More
Significance: Rush's Mill Bridge is one of a small number of composite cast- and wrought-iron bridges yet remaining in the U.S. It is also one of the few existing examples employing the Howe-truss form in whic More
Significance: Rush's Mill Bridge is one of a small number of composite cast- and wrought-iron bridges yet remaining in the U.S. It is also one of the few existing examples employing the Howe-truss form in whic More
Significance: Rush's Mill Bridge is one of a small number of composite cast- and wrought-iron bridges yet remaining in the U.S. It is also one of the few existing examples employing the Howe-truss form in whic More
Significance: Rush's Mill Bridge is one of a small number of composite cast- and wrought-iron bridges yet remaining in the U.S. It is also one of the few existing examples employing the Howe-truss form in whic More
Significance: The oldest extant steel cantilever bridge in Washington. It is a good example of early-twentieth century cantilever bridge construction using carbon steel. The structure served first at Vantage Fe More
Significance: The oldest extant steel cantilever bridge in Washington. It is a good example of early-twentieth century cantilever bridge construction using carbon steel. The structure served first at Vantage Fe More
Significance: The oldest extant steel cantilever bridge in Washington. It is a good example of early-twentieth century cantilever bridge construction using carbon steel. The structure served first at Vantage Fe More
Significance: The oldest extant steel cantilever bridge in Washington. It is a good example of early-twentieth century cantilever bridge construction using carbon steel. The structure served first at Vantage Fe More
Significance: The oldest extant steel cantilever bridge in Washington. It is a good example of early-twentieth century cantilever bridge construction using carbon steel. The structure served first at Vantage Fe More
Significance: The oldest extant steel cantilever bridge in Washington. It is a good example of early-twentieth century cantilever bridge construction using carbon steel. The structure served first at Vantage Fe More
Significance: The oldest extant steel cantilever bridge in Washington. It is a good example of early-twentieth century cantilever bridge construction using carbon steel. The structure served first at Vantage Fe More
Significance: The oldest extant steel cantilever bridge in Washington. It is a good example of early-twentieth century cantilever bridge construction using carbon steel. The structure served first at Vantage Fe More
Significance: The oldest extant steel cantilever bridge in Washington. It is a good example of early-twentieth century cantilever bridge construction using carbon steel. The structure served first at Vantage Fe More
Significance: The oldest extant steel cantilever bridge in Washington. It is a good example of early-twentieth century cantilever bridge construction using carbon steel. The structure served first at Vantage Fe More
Significance: The oldest extant steel cantilever bridge in Washington. It is a good example of early-twentieth century cantilever bridge construction using carbon steel. The structure served first at Vantage Fe More
Significance: The oldest extant steel cantilever bridge in Washington. It is a good example of early-twentieth century cantilever bridge construction using carbon steel. The structure served first at Vantage Fe More
Significance: The oldest extant steel cantilever bridge in Washington. It is a good example of early-twentieth century cantilever bridge construction using carbon steel. The structure served first at Vantage Fe More
Significance: The oldest extant steel cantilever bridge in Washington. It is a good example of early-twentieth century cantilever bridge construction using carbon steel. The structure served first at Vantage Fe More
Significance: One of two nearly identical reinforced-concrete girder trestles on the Historic Columbia River Highway and one of four extant structures on the route that have a distinctive cap and arch concrete More
Significance: One of two nearly identical reinforced-concrete girder trestles on the Historic Columbia River Highway and one of four extant structures on the route that have a distinctive cap and arch concrete More
Significance: One of two nearly identical reinforced-concrete girder trestles on the Historic Columbia River Highway and one of four extant structures on the route that have a distinctive cap and arch concrete More
Significance: One of two nearly identical reinforced-concrete girder trestles on the Historic Columbia River Highway and one of four extant structures on the route that have a distinctive cap and arch concrete More
Significance: A half-viaduct designed to carry pedestrians around the outer edge of a spiral section of roadway around the top of a 725' promontory on the Historic Columbia River Highway. Ingenious use of rein More
Significance: A half-viaduct designed to carry pedestrians around the outer edge of a spiral section of roadway around the top of a 725' promontory on the Historic Columbia River Highway. Ingenious use of rein More
Significance: A half-viaduct designed to carry pedestrians around the outer edge of a spiral section of roadway around the top of a 725' promontory on the Historic Columbia River Highway. Ingenious use of rein More
Significance: A half-viaduct designed to carry pedestrians around the outer edge of a spiral section of roadway around the top of a 725' promontory on the Historic Columbia River Highway. Ingenious use of rein More
Significance: A half-viaduct designed to carry pedestrians around the outer edge of a spiral section of roadway around the top of a 725' promontory on the Historic Columbia River Highway. Ingenious use of rein More
Significance: A half-viaduct designed to carry pedestrians around the outer edge of a spiral section of roadway around the top of a 725' promontory on the Historic Columbia River Highway. Ingenious use of rein More
Significance: One of two existing pony-truss spans built by the Beckel Foundry. Both used variations of Francis C. Lowthorp's 23 June 1857 and 13 March 1860 patented cast lower-chord connections. The Old Mill More
Significance: One of two existing pony-truss spans built by the Beckel Foundry. Both used variations of Francis C. Lowthorp's 23 June 1857 and 13 March 1860 patented cast lower-chord connections. The Old Mill More
Significance: One of two existing pony-truss spans built by the Beckel Foundry. Both used variations of Francis C. Lowthorp's 23 June 1857 and 13 March 1860 patented cast lower-chord connections. The Old Mill More
Significance: One of two existing pony-truss spans built by the Beckel Foundry. Both used variations of Francis C. Lowthorp's 23 June 1857 and 13 March 1860 patented cast lower-chord connections. The Old Mill More
Significance: One of two existing pony-truss spans built by the Beckel Foundry. Both used variations of Francis C. Lowthorp's 23 June 1857 and 13 March 1860 patented cast lower-chord connections. The Old Mill More
Significance: One of two existing pony-truss spans built by the Beckel Foundry. Both used variations of Francis C. Lowthorp's 23 June 1857 and 13 March 1860 patented cast lower-chord connections. The Old Mill More
Significance: One of two existing pony-truss spans built by the Beckel Foundry. Both used variations of Francis C. Lowthorp's 23 June 1857 and 13 March 1860 patented cast lower-chord connections. The Old Mill More
Significance: One of two existing pony-truss spans built by the Beckel Foundry. Both used variations of Francis C. Lowthorp's 23 June 1857 and 13 March 1860 patented cast lower-chord connections. The Old Mill More
Significance: One of two existing pony-truss spans built by the Beckel Foundry. Both used variations of Francis C. Lowthorp's 23 June 1857 and 13 March 1860 patented cast lower-chord connections. The Old Mill More
Significance: One of two existing pony-truss spans built by the Beckel Foundry. Both used variations of Francis C. Lowthorp's 23 June 1857 and 13 March 1860 patented cast lower-chord connections. The Old Mill More
Significance: One of two existing pony-truss spans built by the Beckel Foundry. Both used variations of Francis C. Lowthorp's 23 June 1857 and 13 March 1860 patented cast lower-chord connections. The Old Mill More
Significance: One of two existing pony-truss spans built by the Beckel Foundry. Both used variations of Francis C. Lowthorp's 23 June 1857 and 13 March 1860 patented cast lower-chord connections. The Old Mill More
Significance: One of two existing pony-truss spans built by the Beckel Foundry. Both used variations of Francis C. Lowthorp's 23 June 1857 and 13 March 1860 patented cast lower-chord connections. The Old Mill More
Significance: One of two existing pony-truss spans built by the Beckel Foundry. Both used variations of Francis C. Lowthorp's 23 June 1857 and 13 March 1860 patented cast lower-chord connections. The Old Mill More
Significance: One of two existing pony-truss spans built by the Beckel Foundry. Both used variations of Francis C. Lowthorp's 23 June 1857 and 13 March 1860 patented cast lower-chord connections. The Old Mill More
Significance: First modern bridge constructed on what became the Historic Columbia River Highway. Designed by the premier bridge engineering firm of Waddell and Harrington, which also created the 1912 Steel Br More
Significance: First modern bridge constructed on what became the Historic Columbia River Highway. Designed by the premier bridge engineering firm of Waddell and Harrington, which also created the 1912 Steel Br More
Significance: First modern bridge constructed on what became the Historic Columbia River Highway. Designed by the premier bridge engineering firm of Waddell and Harrington, which also created the 1912 Steel Br More
Significance: First modern bridge constructed on what became the Historic Columbia River Highway. Designed by the premier bridge engineering firm of Waddell and Harrington, which also created the 1912 Steel Br More
Significance: First modern bridge constructed on what became the Historic Columbia River Highway. Designed by the premier bridge engineering firm of Waddell and Harrington, which also created the 1912 Steel Br More
Significance: First modern bridge constructed on what became the Historic Columbia River Highway. Designed by the premier bridge engineering firm of Waddell and Harrington, which also created the 1912 Steel Br More
Significance: First modern bridge constructed on what became the Historic Columbia River Highway. Designed by the premier bridge engineering firm of Waddell and Harrington, which also created the 1912 Steel Br More
Significance: The only stone-veneered reinforced-concrete arch bridge and one of only eight arch spans on the Historic Columbia River Highway. It is the last bridge in the Multnomah County section of the Histo More
Significance: The only stone-veneered reinforced-concrete arch bridge and one of only eight arch spans on the Historic Columbia River Highway. It is the last bridge in the Multnomah County section of the Histo More
Significance: The only stone-veneered reinforced-concrete arch bridge and one of only eight arch spans on the Historic Columbia River Highway. It is the last bridge in the Multnomah County section of the Histo More
Significance: A reinforced-concrete arch pedestrian bridge over the Lower Multnomah Falls. One of the few bridges constructed on the highway strictly for pedestrian use. Survey number: HAER OR-36-I Building/ More
Significance: A reinforced-concrete arch pedestrian bridge over the Lower Multnomah Falls. One of the few bridges constructed on the highway strictly for pedestrian use. Survey number: HAER OR-36-I Building/ More
Significance: A reinforced-concrete arch pedestrian bridge over the Lower Multnomah Falls. One of the few bridges constructed on the highway strictly for pedestrian use. Survey number: HAER OR-36-I Building/ More
Significance: One of the oldest steel truss highway bridges in Oregon and the second oldest steel truss constructed on the Historic Columbia River Highway. Provided a vital link across the Sandy River at the b More
Significance: One of the oldest steel truss highway bridges in Oregon and the second oldest steel truss constructed on the Historic Columbia River Highway. Provided a vital link across the Sandy River at the b More
Significance: One of the oldest steel truss highway bridges in Oregon and the second oldest steel truss constructed on the Historic Columbia River Highway. Provided a vital link across the Sandy River at the b More
Significance: One of the oldest steel truss highway bridges in Oregon and the second oldest steel truss constructed on the Historic Columbia River Highway. Provided a vital link across the Sandy River at the b More
Significance: One of the oldest steel truss highway bridges in Oregon and the second oldest steel truss constructed on the Historic Columbia River Highway. Provided a vital link across the Sandy River at the b More
Significance: This 400' half-viaduct was an engineer's solution to aligning the Historic Columbia River Highway between a steep unstable slope and the Oregon Washington Railroad and Navigation Company main line More
Significance: This 400' half-viaduct was an engineer's solution to aligning the Historic Columbia River Highway between a steep unstable slope and the Oregon Washington Railroad and Navigation Company main line More
Significance: This 400' half-viaduct was an engineer's solution to aligning the Historic Columbia River Highway between a steep unstable slope and the Oregon Washington Railroad and Navigation Company main line More
Significance: This 860' half-viaduct was an engineer's solution to aligning the Historic Columbia River Highway between a steep unstable slope and the Oregon Washington Railroad and Navigation Company main line More
Significance: This 860' half-viaduct was an engineer's solution to aligning the Historic Columbia River Highway between a steep unstable slope and the Oregon Washington Railroad and Navigation Company main line More
Significance: This 860' half-viaduct was an engineer's solution to aligning the Historic Columbia River Highway between a steep unstable slope and the Oregon Washington Railroad and Navigation Company main line More
Significance: This 860' half-viaduct was an engineer's solution to aligning the Historic Columbia River Highway between a steep unstable slope and the Oregon Washington Railroad and Navigation Company main line More
Significance: This 860' half-viaduct was an engineer's solution to aligning the Historic Columbia River Highway between a steep unstable slope and the Oregon Washington Railroad and Navigation Company main line More
Significance: This 860' half-viaduct was an engineer's solution to aligning the Historic Columbia River Highway between a steep unstable slope and the Oregon Washington Railroad and Navigation Company main line More
Significance: The Scarlets Mill Bridge is a cast- and wrought-iron Pratt-type truss with a rolled upper chord arched in the form of an ellipse, one of many built in the 1870s and 1880s for the Philadelphia and More
Significance: The Scarlets Mill Bridge is a cast- and wrought-iron Pratt-type truss with a rolled upper chord arched in the form of an ellipse, one of many built in the 1870s and 1880s for the Philadelphia and More
Significance: The Scarlets Mill Bridge is a cast- and wrought-iron Pratt-type truss with a rolled upper chord arched in the form of an ellipse, one of many built in the 1870s and 1880s for the Philadelphia and More
Significance: The Scarlets Mill Bridge is a cast- and wrought-iron Pratt-type truss with a rolled upper chord arched in the form of an ellipse, one of many built in the 1870s and 1880s for the Philadelphia and More
Significance: The Scarlets Mill Bridge is a cast- and wrought-iron Pratt-type truss with a rolled upper chord arched in the form of an ellipse, one of many built in the 1870s and 1880s for the Philadelphia and More
Significance: The Scarlets Mill Bridge is a cast- and wrought-iron Pratt-type truss with a rolled upper chord arched in the form of an ellipse, one of many built in the 1870s and 1880s for the Philadelphia and More
Significance: The Scarlets Mill Bridge is a cast- and wrought-iron Pratt-type truss with a rolled upper chord arched in the form of an ellipse, one of many built in the 1870s and 1880s for the Philadelphia and More
Significance: The Scarlets Mill Bridge is a cast- and wrought-iron Pratt-type truss with a rolled upper chord arched in the form of an ellipse, one of many built in the 1870s and 1880s for the Philadelphia and More
Significance: The Scarlets Mill Bridge is a cast- and wrought-iron Pratt-type truss with a rolled upper chord arched in the form of an ellipse, one of many built in the 1870s and 1880s for the Philadelphia and More
Significance: The Scarlets Mill Bridge is a cast- and wrought-iron Pratt-type truss with a rolled upper chord arched in the form of an ellipse, one of many built in the 1870s and 1880s for the Philadelphia and More
Significance: The Scarlets Mill Bridge is a cast- and wrought-iron Pratt-type truss with a rolled upper chord arched in the form of an ellipse, one of many built in the 1870s and 1880s for the Philadelphia and More
Significance: The Scarlets Mill Bridge is a cast- and wrought-iron Pratt-type truss with a rolled upper chord arched in the form of an ellipse, one of many built in the 1870s and 1880s for the Philadelphia and More
Significance: The Scarlets Mill Bridge is a cast- and wrought-iron Pratt-type truss with a rolled upper chord arched in the form of an ellipse, one of many built in the 1870s and 1880s for the Philadelphia and More
Significance: The Scarlets Mill Bridge is a cast- and wrought-iron Pratt-type truss with a rolled upper chord arched in the form of an ellipse, one of many built in the 1870s and 1880s for the Philadelphia and More
Significance: The Scarlets Mill Bridge is a cast- and wrought-iron Pratt-type truss with a rolled upper chord arched in the form of an ellipse, one of many built in the 1870s and 1880s for the Philadelphia and More
Significance: The Scarlets Mill Bridge is a cast- and wrought-iron Pratt-type truss with a rolled upper chord arched in the form of an ellipse, one of many built in the 1870s and 1880s for the Philadelphia and More
Significance: The only set of highway tunnels with adits or windows in Oregon. One of the few examples of this type of tunnel in the United States. Survey number: HAER OR-36-T Building/structure dates: 1920 More
Significance: The only set of highway tunnels with adits or windows in Oregon. One of the few examples of this type of tunnel in the United States. Survey number: HAER OR-36-T Building/structure dates: 1920 More
Significance: The only set of highway tunnels with adits or windows in Oregon. One of the few examples of this type of tunnel in the United States. Survey number: HAER OR-36-T Building/structure dates: 1920 More
Significance: The only set of highway tunnels with adits or windows in Oregon. One of the few examples of this type of tunnel in the United States. Survey number: HAER OR-36-T Building/structure dates: 1920 More
Significance: The only set of highway tunnels with adits or windows in Oregon. One of the few examples of this type of tunnel in the United States. Survey number: HAER OR-36-T Building/structure dates: 1920 More
Significance: The only set of highway tunnels with adits or windows in Oregon. One of the few examples of this type of tunnel in the United States. Survey number: HAER OR-36-T Building/structure dates: 1920 More