Twin Metals finalizes plans for huge underground mine in Minn. "We think it will be close to the largest underground mine in the U.S," Twin Metals spokesman Bob McFarlin said of the project, which would resemble a vast underground city. "You've got roads, lights, plumbing, electricity, air circulation -- all those types of things that support an operation of 1,300 employees working underground in shifts, and moving a lot of material." See more at... http://www.prairiebizmag.com/event/article/id/18692/group/Energy%20and%20Mining/#sthash.VOhISLN1.dpuf ..