The collection consists of diazo and blueprint copies of plans for the U.S. Army Corps of Engineers Portland District's projects in Oregon and Washington state. The majority of plans relate to the locks at Willamette Falls in Oregon City, Oregon. These plans illustrate the design of the locks as a whole and of individual components for the lock gates. Other plans in the collection are for modifications to a lock and dam on the Yamhill River near Fayetteville, Oregon; a Spokane, Portland and Seattle Railway station and water tower in Plymouth, Washington; and gun emplacements at Fort Stevens, Oregon.