Clarissa in central Minnesota was interesting. It would be unusual to find a place to camp free in most towns and cities but in Clarissa you can camp free for a week. The latest census showed 609 people in Clarissa, and it's off the beaten path, which probably explains how they can manage to allow free camping - with playground equipment, swimming (in a creek), electricity, barbeques and bathrooms.
It's nice to see the civic pride of people in small town America by taking some of the Blue Highways. Driving north on highway 71 from I-94 you will pass through several small towns including Bertha, Browerville, Long Prairie and Sauk Centre - the home of Sinclair Lewis and the inspiration for his novel Main Street, which provides a less than rosy look at life in a small town. You are also in Lake Wobegon territory, where "all the women are strong, all the men are good looking, and all the children are above average," so it can't be that bad.