These quarries were located "north of Mill Cove, Crotch Island." The operator was S. Clinton Sherwood, 14 Wall Street, New York. The granite in the lower and northern quarry was reportedly a light-gray color with a very slight buff tinge.
The lower quarry was opened in 1889. It covered a triangular area and in 1905 each side measured 75 feet long and 40 feet deep. Transport of the granite was by track 100 feet to the wharf. The quarry was worked only for special orders and produced stone for monuments, bases, etc.
Granite from the upper quarry, which was opened in 1890, was reportedly a pinkish-buff color with a coarse texture. In 1905 the upper quarry measured 200 by 100 feet with an average depth of about 15 feet. Transport of the granite was by cable and engine along a 900-foot track to the dock on the east side of the island. The granite from this quarry was used as "random" stone.