Sault Ste. Marie in Chippewa County, Michigan — The American Midwest (Great Lakes)
The stone that stops Lake Superior
Upper Canal Park, St. Marys Falls Canal
Photographed by Sandra Hughes Tidwell, May 17, 2023
1. The stone that stops Lake Superior Marker
A thick layer of stone holds back the waters of Laker Superior and creates rapids here where the waters of Lake Superior drop 21 feet at the head of the St. Marys River.
Without this layer of stone between Lake Superior and the St. Marys River, the force of flowing water would quickly erode the riverbed and level the two waterways.
The Sault and much of the southern shore of Lake Superior rest on the Jacobsville Formation, a bedrock of reddish sandstone. Up to 1,000 feet in the Sault and along the shore, its color comes from iron trapped in the rock.
Engineers take core samples like this before starting work on each new lock. Understanding the nature of the bedrock is critical when planning new projects.
Erected by US Army Corps of Engineers.
Topics. This historical marker is listed in this topic list: Waterways & Vessels.
Location. 46° 30.117′ N, 84° 21.135′ W. Marker is in Sault Ste. Marie, Michigan, in Chippewa County. It is on East Portage Avenue. Touch for map. Marker is at or near this postal address: 225 E Portage Ave, Sault Sainte Marie MI 49783,
this page online
Regionally, this marker is on Michigan’s Upper Peninsula. It is also in the American Midwest, on the Great Lakes, and on Lake Superiors South Shore Region. Globally, it is in North America, the Great North Woods, the Western Hemisphere, the Western World, and the Anglosphere. Historically, it finds itself in what was once the Viceroyalty of New France and also the Northwest Territory.
Other nearby markers. At least 8 other markers are within walking distance of this marker: American Spirit (a few steps from this marker); Stewart J. Cort (within shouting distance of this marker); Burns Harbor (within shouting distance of this marker); Presque Isle (within shouting distance of this marker); How's the weather? (within shouting distance of this marker); Paul R. Tregurtha (within shouting distance of this marker); Edwin H. Gott (about 300 feet away, measured in a direct line); International Shipmasters Association (about 300 feet away). Touch for a list and map of all markers in Sault Ste. Marie.
Photographed by Sandra Hughes Tidwell, May 17, 2023
2. The stone that stops Lake Superior Marker
Photographed by Sandra Hughes Tidwell, May 17, 2023
3. 36" Diameter Drill Core Tablet
Taken 85 ft. below ground surface from Potsdam Sandstone Edge rock upon which the Soo Locks are constructed. The existence of this ledge rock formation kept Lake Superior 23 ft. higher than Lake Huron & made the locks necessary.
Photographed by Sandra Hughes Tidwell, May 17, 2023
4. 36" Diameter Drill Core
Credits. This page was last revised on August 26, 2024. It was originally submitted on May 26, 2023, by Sandra Hughes Tidwell of Killen, Alabama, USA. This page has been viewed 320 times since then and 24 times this year. Photos: 1, 2, 3, 4. submitted on May 26, 2023, by Sandra Hughes Tidwell of Killen, Alabama, USA. • J. Makali Bruton was the editor who published this page.
