Arch Rock, Mackinac County, Michigan
Photos by Jay Wilbur
NABSQNO 16T-685794-5081031. Arch Rock is a sea natural arch eroded through a remnant of a limestone cliff that was at one time the shore of Lake Nipissing, a predecessor of Lakes Huron and Michigan. Because the lake level has dropped significantly in recent times, leaving the arch isolated and well above the waves, Arch Rock has avoided the usually short lifespan typical of sea natural arches. Indeed, Arch Rock is probably between 3500 and 4000 years old.
A small sea natural arch perforates the eastern abutment of Arch Rock. This small arch, shown above in the insert at lower left, is named Sanilac Arch. This is a good example of an uninteresting natural arch with a grandiose name near a much more important arch that has been given a rather prosaic name.
Arch Rock is located on the east side of Mackinac Island, Michigan. Access is via a ferry from Mackinaw City, followed by a 1.3 mile walk along the paved shore road. It was listed as number 14-1 in the Vreeland catalog. Vreeland reported a span of 50 feet for the arch.