![Sheldon Slate, Monson, ME – The Delta Slate Company](/6ky5vhl/559.jpg)
Sheldon Slate, Monson, ME – The Delta Slate Company
Several quarries adopted tunneling as a means to extract the slate—a technically difficult and laborintensive method. Eventually the quarries fell into minimal use. Rubbish piles are still ground up for road surfacing, while landscapers pick out rock they can use.