I commend you on knowing that the Red River flows south to north. Maybe they did cross over and come through Kensington to get to the Mississippi...IF they knew it was there....,but I can't imagine them leaving the stone in the middle of nowhere (no big landmarks). The tale is they were clearing brush for farming with horses and plow....pretty thick stuff.
Once you pass Fergus Falls and head north on I94, it's flat all the way to Grand Forks (I haven't been north of that). The whole west 1/3 of Minnesota is flat practically treeless (no forests)....as you head east (and north of I94), it becomes very hilly and you see huge forests of trees....especially pines (it's beautiful and remote....called "cabin country" up here).
Andes Tower Hills is a fun place...especially the tubing. Still have a sprained thumb from a few weeks back. It's mostly a "kids" hangout......there's not much to do here during the winter in Minnesota. It's been unusually warm here and the lakes are barely frozen over. Ice houses, snowmobiles (only place to ride right now), and vehicles are going through daily. Snow is practically gone, but expecting some tonight.
including having been involved in the large-scale mining of copper in the Lake Superior region during the Bronze Age: it had always been a mystery where enough copper could have been obtained to even HAVE a "Bronze Age" in the Old World...