Pengilly, MN

ZIP code 55775 covers Soudan, a small community in St. Louis County in northeastern Minnesota, near the southern shore of Lake Vermilion. Its defining landmark is Soudan Underground Mine State Park, which preserves Minnesota’s first underground iron-ore mine. The former mine also houses the University of Minnesota’s Soudan Underground Laboratory, a research facility reached through the mine’s historic shaft and tunnels. The area reflects the region’s mining history and forest-and-lake setting.