The state Department of Natural Resources says zebra mussels have spread to two lakes in western Minnesota.
DNR biologists confirmed that the pests are now in Brophy and Cowdry lakes near Alexandria.
Brophy and Cowdry are part of a small chain of lakes less than a mile upstream of Lake Darling and the Alexandria chain of lakes, which were confirmed to have zebra mussels in 2009.
A homeowner found several zebra mussels attached to rocks in Brophy and reported it to the DNR. The DNR surveyed Brophy and downstream in Cowdry and found young zebra mussels in both lakes.
Nathan Olson, DNR invasive species specialist in Fergus Falls, calls the discovery "very disappointing."
In response, the DNR plans to put up signs and step up its enforcement and watercraft inspections.