Middle Fork Koyukuk: Here at the Koyukuk River, 130 miles north of the Yukon River, this surveyor elected not to use a boat to check the depth of the ditch., 1976-05, PCA0002-1b-17, 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/17355 Accessed February 22, 2025.