During the height of Oregon's covered bridge era, work crews erected hundreds of bridges over the state's rivers with a construction process that began with abutments supporting the ends of the bridge, continued with falsework across the river for building the trusses and deck, and ended with removing the falsework, building the roadway, and adding the roof and siding. Covered bridge building from the 1800s into the 1900s was a specialized trade practiced by skilled builders, including prominent figures such as A.S. Miller, Lord Nelson "Nels" Roney, and brothers Miller and Walt Sorenson. Light covered bridge architecture emphasized simple, functional design, while concerns about light and visibility inside the passage led designers to create distinctively shaped windows between the trusses and subtle variations in portal styles.