Gulkana River: The backbone of the bridge's substructure is unique. The eight specially designed "h"-pilings at each of the bridge's four piers are made of 20-foot-long sections of surplus 48-inch-diameter pipe, filled with concrete. 18-inch-diameter pipe, originally intended for above ground pipeline supports, is used to transfer loads from the bridge to the piers, 1976-05, PCA0002-1b-9, Folder: PCA0002-1b. Alyeska Pipeline Service Company : Trans-Alaska Pipeline Construction Collection, 1976-1977, PCA 2. Alaska State Library - Historical Collections Finding Aids. https://alaska.libraryhost.com/repositories/2/archival_objects/17347 Accessed February 22, 2025.