DULUTH (AP) — The Minnesota Department of Natural Resources confirms that zebra mussels have been found in Sand Lake in Itasca County.

DNR experts confirmed the finding of a homeowner who found adult zebra mussels attached to a dock removed from Sand Lake last fall.

Preliminary searches of connected waters also found zebra mussels in Little Sand Lake.

Sand Lake and Little Sand Lake are part of a chain of lakes that eventually flow into Bigfork River.

Additional searches of connected waters are being performed to determine the scope of the infestation.

Zebra mussels continue to spread across Minnesota. The tiny pests first were discovered in the Twin Ports harbor decades ago after moving into the Great Lakes in the ballast of ships from Europe and Russia.