Gilbert, MN (Northland's NewsCenter) -- The Minnesota Department of Natural Resources says that they discovered zebra mussels in Gilbert Pit near Gilbert in St. Louis County.
Futher inspections were made by a DNR invasive species specialist to confirm the extent of the infestation.
Adult zebra mussels were located in a mass approximately 250 yards south of the pit's boat access.
Most of the zebra mussels were large and none less than 1 centimeter were located, the DNR says.
"This is the first time we've located zebra mussels in a mine pit lake, and it's the furthest north in the state where we have found them," said Rich Rezanka, invasive species specialist. "It's another reminder that aquatic invasive species can travel great distances and don't have to be in a near-by lake or river to be a threat."
Boaters who use Gilbert Pit are asked to be extra thorough when decontaminating their boats, trailers, anchors, and other equipment when leaving the lake.
It is unlawful in Minnesota to transport aquatic plants or prohibited invasive species on roads or to launch watercraft with them attached.