Duluth and the Iron Range have been economically connected since the beginning of the iron ore industry. Railways bring ore from the Mesabi range to Duluth, and limestone from Duluth ships to the iron ore plants. Limestone is used (as well as clay) as a binding agent to make taconite pellets. Until 2004, the rail was run by Duluth, Missabe and Iron Range Railway. It was purchased by Canadian National (CN), but the DMIR logo still graces the sides of many cars. Have a look and listen to my early explorations of the railway and loading docks in Duluth.