Extent of available data.
This data layer indicates the locations of documented mine shafts within the Mesabi Range. It was developed by the Minnesota Department of Natural Resources. Shafts are vertical or inclined passages from ground surface to underground orebodies that allow access/egress of people and materials and provide for mine ventilation and dewatering. This information can be used for mapping, documentation, potential energy storage exploration (pumped hydro, compressed air), monitoring, analysis, and land use planning purposes.