These drawings document ruins of canal locks that remain from the earliest era of the Erie Canal. They were discovered beneath industrial buildings in Cohoes, New York. The color map was finished in Adobe Illustrator. Additional locks were located using a handheld Trimble GPS unit and imported into ArcGIS.  Historic maps were consulted to produce the conjectural view of what the locks once looked like and to draw the patterns of development in the area over time. Laser scan data provided the information needed to complete the longitudinal section of the lock ruins  beneath the buildings.