Mackinac Island in Mackinac County, Michigan — The American Midwest (Great Lakes)
Sanilac Arch
Photographed by Joel Seewald, July 1, 2025
1. Sanilac Arch Marker
Arch Rock rests on a limestone breccia promontory nearly 150 feet above Lake Huron. Tunnel-like Sanilac Arch pierces the southern abutment near its base. Both arches were formed about 4,000 years ago by wave action of ancient Lake Nipissing. Once called Maiden Arch, the smaller opening was renamed Sannillac Arch in 1913, after the Wyandot leader Sannillac. Its name was eventually shortened to Sanilac Arch.
Visitors once walked through Sanilac Arch from the lakeshore. More agile explorers approached from above, following a treacherous pathway directly beneath Arch Rock. Debris from the disintegrating cliffside slowly filled the lower arch and access is no longer permitted.
Topics. This historical marker is listed in this topic list: Natural Features. A significant historical year for this entry is 1913.
Location. 45° 51.471′ N, 84° 36.37′ W. Marker is on Mackinac Island, Michigan, in Mackinac County. It is on Lake Shore Boulevard (State Highway 185), on the right when traveling north. Marker is just north of mile marker 1. Touch for map. Marker is in this post office area: Mackinac Island MI 49757, United States of America.
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Regionally, this marker is on Michigan’s Upper Peninsula and on the Straits of Mackinac. It is also in the American Midwest and on the Great Lakes. 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: Arch Rock: Unsurpassed in Nature's Handiwork (here, next to this marker); Gitchie Manitou (here, next to this marker); The Center of the Anishnaabek World (within shouting distance of this marker); Nicolet Watch Tower (within shouting distance of this marker); Arch Rock (within shouting distance of this marker); Dwightwood Spring (about 800 feet away, measured in a direct line); Fort Holmes (approx. half a mile away); Resting Place of the Ancestors (approx. half a mile away). Touch for a list and map of all markers in Mackinac Island.
2. Sanilac Arch Marker left image
3. Sanilac Arch Marker right image
Photographed by Joel Seewald, July 1, 2025
4. Sanilac Arch
Photographed by Joel Seewald, July 1, 2025
5. Sanilac Arch Marker
This marker is the one on the right.
Credits. This page was last revised on July 10, 2025. It was originally submitted on July 10, 2025, by Joel Seewald of Madison Heights, Michigan. This page has been viewed 132 times since then and 25 times this year. Photos: 1, 2, 3, 4, 5. submitted on July 10, 2025, by Joel Seewald of Madison Heights, Michigan.
