View of Lock 18, around 1900. Lockhouse in background was destroyed later on.
National Park Service, US Govt
NPS <a rel="nofollow" class="external free" href="https://www.nps.gov/choh/learn/historyculture/upload/Locks-Masonry-HSR-Unrau.pdf">https://www.nps.gov/choh/learn/historyculture/upload/Locks-Masonry-HSR-Unrau.pdf</a>