A naturalist friend was over for dinner and I gave her samples to verify his identification.
The day after my son’s 11th birthday, we went to the beach and I found this shovel handle (no shovel, just the handle).
I called Crystal Lake Park District Director Kirk Reimer to ask if they had been found before.
He told me that Dick Vogelman had found them on his Shore Station two years ago. Vogelman lives at Gate 7 right next to the Country Club Property Owners boat launching ramp.
So, a plausible hypothesis might be that some CCAPOA boater was in Lake Michigan and didn’t clean the mussels off his boat before launching it in Crystal Lake.
As usual, the photo can be enlarged by clicking on it.