With its frozen lakes, pine and spruce-studded woodlands and myriad animal tracks, Minnesota's north country is home to a network of mostly flat trails. The trail system however, stretches from Lake Superior to the Canadian border with more than 250 miles of classic tracks. While the air is as cold as it gets in North America, there's serious comfort at night with the Gunflint Lodge or the Finnish-sauna-equipped Tall Pines Yurt. Let Boundary Country Trekking transport your gear and food ahead on a snowmobile. They can even cook up a Mongolian fire-pot dinner. No trail fees. [visitcookcounty.com]