Between the railroad tracks on the Minnesota side and the tracks on the Wisconsin side are boundary waters and can be fished with either liscense. If he has a Minnesota liscense he has to follow these rules.
WISCONSIN–MINNESOTA Regulations
• Two lines with a single lure or bait on each are permitted. If fishing with one line you may use two baits.
• Fish hooked in any part of the body except the mouth must be returned to the water immediately.
• Tip-ups must be within 400 feet of the angler.
• Rough fish may be taken by spearing, archery, and dip-netting during daylight hours from May 3, 2008 through March 1, 2009. Dip net hoops cannot exceed 24 inches in diameter.