| Specimen ID | 116420 |
| Group | Mollusks-Bivalves |
| Genus | Dreissena |
| Species | polymorpha |
| Common Name | zebra mussel |
| State | IL |
| County | Cook |
| Locality | Lake Michigan, Monroe [St.] Harbor (Chicago Harbor), Chicago, IL |
| Mapping Accuracy | Accurate |
| HUC8 Name | Lake Michigan |
| HUC8 Number | 04190000 |
| HUC10 Name | Lake Michigan |
| HUC10 Number | 0419000002 |
| HUC12 Name | Lake Michigan |
| HUC12 Number | 041900000200 |
| Map | |
| Collection Month | 10 |
| Collection Year | 1991 |
| Year Accuracy | Actual |
| Potential Pathway | shipping |
| Status | established |
| Comments | Boat was covered with mussels. Had been in the water for two seasons. |
| Record Type | Personal communication |
| Freshwater/Marine | Freshwater |
