Underground Mining Museum Mining at this site continued until 1967, marking the tip of underground iron mining within the area. The Iron Cliffs Company was established in 1865 by a group of New Yorkers together with Samuel J. Tilden. They obtained property in Marquette County and opened their first http://arthurpppp5.tinyblogging.com/Effects-Of-Rock-Dust-Applications-On-Coal-Mine-Dust-Measurements-44425537