The Missouri Department of Conservation says zebra mussels have been found in Smithville Lake, a reservoir north of Kansas City.
The Kansas City Star reports the invasive mussels were found attached to metal gates that control the flow of water through a dam, and to a dock at the boat ramp near the Camp Branch Marina.
Zebra mussels pose no health risk to humans, but they multiply rapidly and are almost impossible to eliminate from large lakes once they're established.
Dense colonies can clog water lines and intakes and crowd out native species. They spread in flowing water, and also travel within boats and bait buckets, and by attaching themselves to hulls.
Smithville Lake is the fifth Missouri reservoir where zebra mussels have been found.