Archaeological Management Plan for the Regional Municipality of Durham ROP Consolidation September 3, 2024.The Iroquois shoreline is the prehistoric shoreline of Glacial Lake Iroquois. This lake existed at the end of the last ice age (approximately 12 000 years ago). The layer was created by determining the edge of the shore by selecting the shorecliffs of the current landscape, which is a characteristic of this particular glacial lake.

This is a georeferenced raster image of a printed paper map of the Iroquois Falls, Ontario region (Sheet No. 042A15), published in 1976. It is the second edition in a series of maps, which show both natural and man-made features such as relief, spot heights, administrative boundaries, secondary and side roads, railways, trails, wooded areas, waterways including lakes, rivers, streams and rapids, bridges, buildings, mills, power lines, terrain, and land formations. This map was published in 1976. Maps were produced by Natural Resources Canada (NRCan) and it's preceding agencies, in partnership with other government agencies. Please note: image / survey capture dates can span several years, and some details may have been updated later than others. Please consult individual map sheets for detailed production information, which can be found in the bottom left hand corner. Original maps were digitally scanned by McGill Libraries in partnership with Canadiana.org, and georeferencing for the maps was provided by the University of Toronto Libraries and Eastview Corporation.

During the review of the Carruthers Watershed, it came to the attention of TRCA hydrogeology staff that the Iroquois Shoreline in the Geologic Folder of the TRCA corporate data layers did not follow the Physiography established by Chapman and Putnam 1984 (The Physiography of Southern Ontario). It was then noted that within the Duffins Watershed the shoreline did not extend north along the Duffins River nor turn south along the height of land at the hamlet of Greenwood - instead the shoreline appeared to offset by about 1 km. TRCA hydrogeology staff brought the issue forward with Dr. Rick Gerber of the YPDT-CAMC team who stated that he had noticed the same thing when he prepared the Duffins and Carruthers watershed report in the early 2000s. He believed the error to be a NAD 83 / 27 conversion error.