The above view of Lake St. Catherine looks upon the lake from the hills of South Poultney, Vermont and easterly towards the Taconic Mountain range and Wells, Vermont.

        About two miles south of the village of Poultney, the "Gibson Quarry" was discovered and opened by Owen Williams in 1864.   This was the first slate opening in this southern section of  Poultney.  Not long after this quarry was opened it was purchased by a Schenectady company, and "has since been worked by it, as also was another called the 'Schenectady Quarry'," according to Frisbee & Joslin's History of Poultney written in 1875.  It noted the slate to be a "good quality."
        A short distance north of the Gibson and Schenectady quarries was another quarry known as the "Horton Quarry."  It was opened in 1871 by Cyrus E. Horton and produced a superior quality of roofing slate of the green variety.
        What was known as the "Green Mountain Slate Vein" was discovered in 1866 by William R. Williams, and was an opening made by him and his brother, John R. Williams.  This was on land about one hundred rods east of the railroad tracks.  The History of Poultney includes considerable information about the quarries in this region of the Slate Valley.
        Today, the largest quarry operation in the Slate Valley is located in South Poultney.  Known for many years as Hilltop Slate Company, it is now owned by McAlpine of Bethesda, North Wales, owners of the large Penrhyn Quarry in that country.  McAlpine's Vermont slate is quarried in South Poultney as well as nearby Wells and taken to their mill in nearby Middle Granville, New York for processing.  Several colors of slate are found in quarry sites in South Poultney including sea greens and purples.