Lake Vermilion–Soudan Underground Mine State Park. Photograph by Minnesota Department of Natural Resources Staff, March 8, 2010.

Beaver dam in Lake Vermilion–Soudan Underground Mine State Park. Photograph by Minnesota Department of Natural Resources Staff, May 21, 2014.

Hiker on rocky hill in Lake Vermilion–Soudan Underground Mine State Park. Photograph by Minnesota Department of Natural Resources Staff, October 30, 2007.

Rocky shoreline in Lake Vermilion–Soudan Underground Mine State Park. Photograph by Minnesota Department of Natural Resources staff.

Picnic shelter in Lake Vermilion–Soudan Underground Mine State Park. Photograph by Minnesota Department of Natural Resources Staff, May 22, 2014.

Front face of the MINOS far detector. On the left is the control room; on the right is a mural by Joseph Giannetti.

Stuntz Bay boathouses on Lake Vermilion, Soudan Underground Mine State Park, 2011. Photograph by Wikimedia Commons user McGhiever.

Underground (twenty-seven levels below the surface) miners’ lunchroom in the Soudan Iron Mine, Lake Vermilion–Soudan Underground Mine State Park.

Sign inside the Soudan Mine in Lake Vermilion–Soudan Underground Mine State Park, July 16, 2005.

Jaspilite-banded iron formation in the Stuntz Bay Road outcrop, Soudan Underground State Park, Soudan, June 10, 2015. Photograph by Wikimedia Commons user James St. John.