Invasive mussels were found on a Minnesota boat headed to Whitefish Lake on Wednesday.

The boat was intercepted in Browning, where Blackfeet Fish and Wildlife has been working with the Flathead Basin Commission, which works to keep invasive species out of the area.

Inspectors Jay Monroe and Rick Hoyt identified adult zebra mussels attached to the boat motor.

“The owner was extremely cooperative in terms of delaying his launch and undergoing a decontamination process,” Monroe said in a news release.

Earlier this year, the Blackfeet Tribe opened the check station for boats.

Caryn Miske, the commission’s executive director, added that another potentially fouled boat was intercepted by the tribe on Thursday. That boat from Oklahoma was bound for Lake Koocanusa.

“It’s questionable. The boat had been decontaminated in Wyoming, but when our inspectors took a look at it, there were still byssal threads, but they were completely dry.”

Byssal threads are what zebra and quagga mussels use to attach to hard surfaces, and while Miske said the boat was likely no longer contaminated, the presence of the threads made it “high risk.”

Wildlife officials were still decontaminating the boat on Friday.