Eugene/Architecture/Alphabet: X

Onyx Bridge framed by Cascade Hall on the left and Willamette Hall on the right (all photos by me).

This is the next in my Eugene/Architecture/Alphabet series of blog posts, the focus of each being a landmark building here in Eugene. Many of these will be familiar to most who live here but there are likely to be a few buildings that are less so. My selection criteria for each will be threefold:

1. The building must be of architectural interest, local importance, or historically significant.
2. The building must be extant so you or I can visit it in person.
3. Each building’s name will begin with a particular letter of the alphabet, and I must select one (and only one) for each of the twenty-six letters. This is easier said than done for some letters, whereas for other characters there is a surfeit of worthy candidates (so I’ll be discriminating and explain my choice in those instances).

This entry’s selection begins with the letter X, for which my choice is Onyx Bridge, located on the University of Oregon campus. The alphabet backed me into a corner. I’m not aware of any prominent building in Eugene whose name begins with “X,” so I had to cheat. With Onyx Bridge, I have a selection whose name at least contains the elusive letter.

South elevation.

Onyx Bridge

The Portland firm of Lawrence, Tucker, and Wallmann designed Onyx Bridge in 1962 as an east wing addition to the University of Oregon’s original Science Building, now known as Pacific Hall. The name refers to Onyx Street, which once extended through the site and intersected with 13th Avenue. Construction closed the street, and the University never reopened it. The building now connects Pacific Hall and Klamath Hall, spanning above the Cascade Annexes and the vacated street. 

Onyx Bridge occupies a prominent position on campus, anchoring the north side of the Onyx quadrangle and linking key science buildings. Its exposed structural system conveys a clear and expressive concept, consistent with architectural priorities of its time. The diagonal steel trusses define the exterior and carry the structural load, eliminating the need for internal bearing walls. This system enabled flexible interior layouts that accommodated evolving scientific research. Original plans proposed four additional stories, bringing the total to eight, but the expansion never occurred. 

The unique design is not without its drawbacks. Faculty reported “too few windows and vibration,” according to the University of Oregon’s 2006 Historic Resource Survey for Onyx Bridge. The windows follow no consistent exterior rhythm, reflecting interior function rather than formal composition. A flat roof, standardized metal-framed windows, and a palette of concrete and steel reinforce the building’s utilitarian character. 

The wall treatments behind the trusses—particularly the irregular fenestration and utilitarian cladding—appear inelegant and ad hoc, weakening the coherence of the overall composition. Exposed ductwork on the north elevation, which I assume was added years after the building’s initial construction, further complicates the visual logic and suggests expedient retrofitting rather than integrated design. 

North elevation. Cascade Annex is in the foreground; Pacific Hall is to the right.

The University Planning Office evaluated the building as having “good integrity” but “very low significance.” This assessment relied on internal criteria for preservation priority, including architectural distinction, historical associations, and integrity of design and materials. Based on those standards, the Planning Office judged Onyx Bridge as unlikely to be eligible for inclusion on the National Register of Historic Places. 

Although the building has not received formal recognition for architectural distinction, its structural expression implies a higher architectural ambition, one that sought but was not entirely successful in elevating its functional brief with clarity, restraint, and formal legibility. 

Within the context of this alphabetic series, Onyx Bridge did offer me a practical solution to my naming challenge, while serving as a relevant example of mid-century institutional architecture in Eugene.