Arch Rock
A rare breccia limestone arch stands high above the east shore, reached by stairs, road, trail, bicycle, or carriage within Mackinac Island State Park.
Artwork inspired by Julius Rolshoven
The arch is a remnant of erosion along an ancient postglacial shoreline, not a bridge carved by the modern lake at its present level. Fractures, solution, waves, and collapse removed surrounding rock while the stronger span remained.
Approach from both the upper overlook and shoreline road to understand height and orientation. Stay behind barriers: climbing damages fragile limestone and a fall reaches steep talus below.
- Height
- About 146 feet above shore
- Rock
- Mackinac breccia limestone
- Approach
- Foot, bicycle, or carriage
Quick guide
- Begin with
- Read the form at limestone span
- Look closely at
- Find the process in Lake Huron frame
See Arch Rock from above and understand its isolation
- Use the upper overlook
- The accessible road approach frames limestone against Lake Huron
- Compare shore level
- Stairs and steep natural routes reveal the span’s elevation
- Notice resistant stone
- Differential erosion left the narrow arch above former shoreline
- Avoid crowd timing
- Carriage tours and bicycles concentrate visitors at predictable intervals
Good to know
The upper viewing deck can be reached without climbing the long shoreline staircase by using interior roads, carriage, or an accessible transport plan.
Notice these
- limestone span
- Lake Huron frame
- Nicolet Watchtower