International Falls, MN
On the United States-Canada border, with Fort Frances, Ontario, two miles north across the Rainy River. Class D, two runways (13/31 at 6,500ft, 4/22 at 3,500ft). International Falls earned its nickname — "Icebox of the Nation" — by recording more days at or below 0°F than any other US city; the official cold record at the field is -55°F, set January 6, 1909. The Canadian Customs and Border Protection facility on-field handles general aviation arrivals; pilots from the Twin Cities flying to Lake of the Woods or Lake Superior's north shore clear in here. Boise Cascade's International Falls paper mill, on the riverbank east of downtown, has been the city's largest employer since the 1950s — the steam plume is often visible from 30 miles out.
A water-based national park on the Canadian border just east of International Falls. Named for the French-Canadian fur traders who paddled birchbark canoes through these lakes in the 1700s and 1800s, carrying beaver pelts from the Canadian interior to Lake Superior. Voyageurs is roughly 40% water — Rainy Lake, Kabetogama Lake, Namakan Lake, and Sand Point Lake make up most of the park, all interconnected and navigable. The park has no road access to its interior; visitors travel exclusively by boat in summer or snowmobile in winter. Northern lights are visible from the park about 200 nights a year due to the high latitude and dark skies — the entire park is designated an International Dark Sky Park.
On the north edge of Hibbing, the Mesabi Range opens into a canyon nobody intended: the Hull-Rust-Mahoning pit, the largest open-pit iron mine in the world, three and a half miles long and around 535 feet deep. They call it the Grand Canyon of the North, and from the air the comparison holds; stepped red and grey benches falling away in terraces. It began in 1895 as a scatter of separate mines that grew into each other. The town of Hibbing was originally next to the ore; in 1919 they moved the town, buildings and all, a couple of miles south so the mine could keep expanding. At its WWI and WWII peak it produced a quarter of all the iron ore in the country, which is most of the reason the United States could out-build everyone in steel. Still active, still getting bigger.
A million-acre wilderness along the US-Canada border in northeastern Minnesota — 1,175 named lakes connected by portages, no roads, no motors, no permanent structures. The BWCAW gets roughly 165,000 paddlers annually, all entering by permit from designated entry points. Adjacent to Canada's Quetico Provincial Park, the combined cross-border wilderness covers 2.4 million acres of the Canadian Shield. The lakes occupy ancient bedrock depressions scoured by Pleistocene ice sheets; the bedrock itself is 2.7 billion years old, among the oldest exposed rock on the continent. Forest is boreal — black spruce, jack pine, white birch, paper birch, balsam fir. From the air the wilderness reads as a continuous mosaic of dark forest punctuated by hundreds of irregularly-shaped lakes.
The source of the Mississippi River — a knee-deep stream you can walk across, flowing out of Lake Itasca in north-central Minnesota. From this point the river runs 2,348 miles south to the Gulf of Mexico, gathering water from 31 states and two Canadian provinces along the way. Henry Schoolcraft, a federal Indian agent with an Ojibwe guide named Ozawindib, identified Itasca as the true headwaters in 1832 — Schoolcraft coined the name from the Latin "verITAS CAput" (true head). The lake is itself glacial, gouged out of bedrock by the Laurentide Ice Sheet about 12,000 years ago. Itasca State Park surrounds the headwaters; the original 1891 protection of the area made it Minnesota's first state park. The stream emerging at the headwaters is about 18 feet wide and one foot deep.