Pineville, Mo. ? Planning to canoe the Elk River? You better keep your clothes on.

McDonald County Commissioners passed a law Wednesday banning nudity on the southwest Missouri county’s waters. Violators can be fined up to $1,000.

Officers will begin enforcing the law immediately, McDonald County Sheriff Robert Evenson said.

Commissioners took the action after the sheriff’s wife and another woman were attacked over the weekend at a private beach in an area along the Elk River, near Pineville.

A group of about 20 canoeists — including several topless women — rounded a curve on the river near the beach, authorities said. Diane Smith, who was with Evenson’s wife and owns property in the subdivision, asked the women to cover themselves because there were children present, authorities said.

Smith told authorities that some people in group started cursing and assaulting them.

Prosecutor Steve Geeding and the commissioners had been discussing for several weeks an ordinance that would ban nudity on the river, but the incident prompted them to take a more immediate action on the subject.

“It was a horrible experience, but at least something good came out of it,” said Smith, of Bella Vista, Ark.

Michael Royal, 26, of Olathe, Kan., faces charges, including assault and endangering the welfare of a child, in the incident. He was released on $50,000 bond.

Geeding said counties in Arkansas on the Illinois River have similar ordinances, but he could not find anything similar regarding waterways in Missouri.