It's called the Stone Barn, and it's a hike to get to. It's out in Nelson, WI, which is about 80 miles from St Paul. It's a pizza restaurant inside an old stone barn on a farm. They do wood fired thin crust pizzas. The meats are locally sourced, and the herbs/veggies are grown by them. We had a Supreme and a Margherita pizza. The Margherita was tops, mainly because of the fresh, very flavorful basil leaves, but the Supreme was excellent too. Just the smell as you walk in is almost worth the drive.
This is not a formal place. It has a small indoor dining room and a much larger outdoor patio that's built in what used to be the back half of the barn. Paper plates, plastic utensils, and if you want a soda, it comes in a can, but the pizzas are great, and the drive out there is scenic, especially if you take Hwy 35 along the river from Prescott. Judging by the number (and class) of cars in the parking field, I'm not the only one who thinks so.
Unfortunately, this review is coming a bit late - they close for the season on the 25th, but it's one to think about for next year.