an Entity references as follows:
The Bruce Mine Headframe is the headframe of a former underground mine in Chisholm, Minnesota, United States. It was built 1925–26 and operated until the mine closed in the early 1940s. The Bruce Mine Headframe was listed on the National Register of Historic Places in 1978 for its state-level significance in the theme of engineering. It was nominated for being the last standing example of the headframes that once proliferated on the Mesabi Range. Most of the other headframes were dismantled as open-pit mining overtook underground mining as the dominant extraction method in the region.