The exposed slate ledge shown here is known as the Glen Lake Syncline located in West Castleton, Vt. In the early 1800s, farmers working fields along the Vermont-New York border below Lake Champlain encountered similar outcroppings of slate. Initially, the region’s surface slate—left exposed by glacial scouring during the Great Ice Age—was quarried on a small scale for mill stock and foundation stone. See “Geology of the Champlain Valley” for the geologic origins of this metamorphic rock. Photo by Tim Healey
Three miles southwest of the Glen Lake Syncline, the first slate quarry in western Vermont was opened in 1839. The quarry owners began manufacturing roof slate 1848 and by 1850 there were five companies in Rutland County, Vermont producing the roofing product. Photo by Tim Healey
A slate quarry in Granville, NY. circa 1920. As quarry pits got wider and deeper, aerial carriages run on steel cables held aloft by “quarry sticks” were needed to hoist the stone out of maturing pits. According to The Slate Roof Bible by Joseph Jenkins, “By 1872, over 11,000 tons of roofing slate were being shipped annually from Poultney, Vermont, amounting to about 35,000 squares of roofing— enough to cover roughly 3,000 average houses.” Image courtesy of the Slate Valley Museum
A slate quarry in Granville, NY. circa 1920. Shanties (where slate was processed) line the left side of the yard while stacked slate piles line the right. A narrow-gauge rail, seen in the center of the photo, was used to move heavy blocks of slate, waste rock, and finish products around the quarry. The completion of the Rutland and Washington Railroad line through Castleton, Poultney, and Granville in 1852 vastly expanded the market for slate beyond the local area to other parts of the northeast and the Midwest. By the turn of the century, up to 250,000 squares of roofing slate were being shipped annually from the slate valley; peaking at 400,000 squares in 1908. Image courtesy of the Slate Valley Museum
Two workers suspended from an aerial carriage over a quarry pit in West Pawlet, Vt. From the Slate Roof Bible, “Slate quarrying was a hazardous occupation due to the cleavage of the stone and the different natural cuts and joints. Undermining was a common cause of accidents, as was carelessness and faulty equipment. The use of black powder and dynamite added to the perilous nature of this trade. There was no workers' compensation, nor were there safety inspections in the early years. The responsibility for safety rested upon the shoulders of the operators and supervisors.” Image courtesy of the Slate Valley Museum
Workers receive a slate block from the quarry pit (left), then split the block up with hammers and chisels (right) (Eureka Quarry in North Poultney, Vt. circa 1948). After its peak in 1908, the slate industry began a slow decline and all but collapsed by the end of World War II. See video, “Heavy Lifting: A Human & Technological History of Moving Slate from Quarry to Market”, for more information about Slate Valley’s unique history. Images courtesy of the Slate Valley Museum