The Michigan Supreme Court has turned down an appeal in a dispute over exotic pigs in the Upper Peninsula.

A Marquette County judge in 2016 said 10 pigs violated state restrictions on Russian boars and should be destroyed. The appeals court affirmed that decision, and the Supreme Court won't intervene.

The Department of Natural Resources designated Russian boars and other exotic swine as an invasive species. The state says they've escaped from hunting ranches and small farms and ravaged the environment.

Lawyers for game ranch owner Greg Johnson of Negaunee Township say the pigs can be traced to domestic breeds.