The bridge builder

A visual feast, the Oregon Coast Highway provides stunning coastal views, crashing waves, beautiful lighthouses and many striking bridges over rivers, bays, and inlets. Many of the impressive concrete and arched span bridges were constructed during the 1920s and ’30s…

A visual feast, the Oregon Coast Highway provides stunning coastal views, crashing waves, beautiful lighthouses and many striking bridges over rivers, bays, and inlets. Many of the impressive concrete and arched span bridges were constructed during the 1920s and ’30s as the automobile started to change the lifestyle and infrastructure of America forever. These bridges were and still are an integral part of the state’s nationally recognized highway system. Their creator, Conde Balcom McCullough, became a passionate promoter of state-sponsored bridge building, incorporating engineering efficiency with economic practicality and aesthetic appeal.
McCullough, known informally as “Mac,” was born on May 30, 1887, near Redfield, S.D. In 1891, his family relocated to Iowa. McCullough was a hard worker from a very young age, supporting his family with odd jobs after his father’s death in 1904.
While working, he remained dedicated to his education, earning undergraduate and graduate degrees in civil engineering from Iowa State College by 1910. McCullough started his career working for James Barney Marsh, owner of the Marsh Bridge Company in Des Moines, Iowa. Marsh patented the rainbow arch design, which McCullough used later in his design of the Yaquina Bay Bridge in Newport, Ore. Variations of this design are seen in most of the smaller spans along the Oregon coast.
After a year, McCullough left Marsh to work for the Iowa State Highway Commission. Drawn to the Northwest because he knew bridges were needed there, in 1916, McCullough took a job at Oregon State Agricultural College (today known as Oregon State University) as the one-man leader of the structural engineering program. He settled in Corvallis, Ore., with his wife and son. Within two years he was full professor and head of the civil engineering department.
In 1919, McCullough became Oregon’s state bridge engineer, going on to lead the Oregon State Highway Department’s bridge design and construction program for 18 years. By 1932, McCullough took on the added administrative responsibilities of assistant state highway engineer. During these years with the OSHD, McCullough became one of the leading bridge engineers in the United States.
McCullough’s portfolio of work includes hundreds of structures and over 30 arched spans. Many of his bridges are rich in architectural detail, embellished with classical, gothic, and art deco/modern elements. For example, Old Youngs Bay Bridge, a double leaf bascule drawspan constructed in 1921, located in Astoria, has large Art Deco Style wood and concrete pylons on both ends of the bridge — trademarks of a McCullough bridge. Old Youngs Bay Bridge and many of McCullough’s designs are located on U.S. Route 101, a major north—south U.S. Highway, known as the Oregon Coast Highway No. 9, which runs between the Pacific Ocean and the Oregon Coast Range, and in many areas is the only viable route connecting certain coastal communities. This highway is also the location of the pinnacle of McCullough’s career: the 1936 completion of five major bridges — the Yaquina Bay Bridge in Newport, the Alsea Bay Bridge in Waldport, the Siuslaw River Bridge in Florence, the Umpqua River Bridge in Reedsport, and the Coos Bay Bridge in Marshfield/North Bend.
According to the Oregon Department of Transportation, “Most impressive is the mile-long span at Coos Bay, a graceful concrete and steel structure of rhythmic beauty that flows across the open water. This bridge and others along Oregon’s ‘blue highways,’ are McCullough’s legacy.”
As design work was complete on the five major Oregon Coast Highway bridges in 1935, McCullough’s career took an international turn as he traveled to Central America to design several structures for the Inter-American Highway. These included suspension bridges over the Rio Chiriqui in Panama, the Rio Choluteca in Honduras, and the Rio Tamasalupa in Guatemala. Upon his return to Oregon in 1937, McCullough left bridge designing for other administrative duties within the OSHD. He died from a stroke in 1946, just weeks short of his 59th birthday.
The Oregon Department of Transportation cites a 1999 ENR honorary 125th anniversary publication, which included a feature of a list of the top people who had made outstanding contributions to the construction industry since 1874. “Their efforts,” ENR noted, “helped shape this nation and the world… by developing new analytical tools, equipment, engineering or architectural design.” McCullough was among the 10 bridge engineers who made the list, which also included Othmar Ammann, James Eads, Robert Maillart, and David Steinman.
In 2005, 12 of McCullough’s bridges were listed in the National Register of Historic Places. Though many of McCullough’s beautiful bridges are still in use today, he is also honored by an interpretive center, located at the south end of the New Alsea Bay Bridge, constructed in 1991, which documents the old bridge and features the life and work of McCullough.
Christina M. Zweig is a contributing editor. She can be contacted at christinaz@zweigwhite.com.