Sanilac Petroglyphs Historic State Park

Location: Cass City, Michigan

Webpage: Michigan State Park

General Description: Sanilac Petroglyphs Historic State Park is the site of the only known Native American Indian rock carvings in Michigan.  The 1,000 square foot sandstone rock has a multitude of symbols and drawings scratched into the relatively soft rock dating from 300 to 1000 years old.  Unlike many known petroglyphs on cave walls, these petroglyphs have been etched into a horizontal stone that is open to the weather.  Natural weathering, along with modern graffiti and vandalism has drastically reduced the number of visible petroglyphs on the surface.  In the mid-1900s a wooden roof and high fence were constructed to protect the petroglyphs with only moderate success.  Although protected somewhat from the rain, the shady conditions have promoted the growth of moss and lichen which are causing further damage to the remaining petroglyphs.



1) The location of the petroglyphs  is at a relatively remote location in the state, which limits the number of visitors.  Even with the damage it is an impressive collection of symbols and drawings, especially since it is on a relatively flat rock out in the open instead of on rock walls in a cave or overhang.  Some of the petroglyphs are easily seen and understood, but the great majority are little more than shallow depressions in the rock.  It was a great help that there was a volunteer interpreter that we spent nearly 45 minutes with discussing the different symbols.  He was clearly an expert on the images and added a lot to our understanding and enjoyment of the site.

2) There is also a 1-mile loop trail that crosses the Cass River, which was much larger in the past before the draining of the surrounding agricultural fields to lower the water table.  The river crossings are over suspended swinging bridges that were themselves interesting.  Unfortunately, one of the bridges had collapsed so the trail became 0.75 each way to the river and back.  Except for the prevalent mosquitoes, it was a pleasant walk augmented by the interpretive signs along the way.  The old military road was pointed out, as well as, the site of an old logging camp.