The Shickshock Mountains constitute one of the highland areas that have been considered by Coleman on geologic evidence, and by Fernald on botanical and geologic evidence, to have been nunataks during the maximum of Wisconsin glaciation.
Recent field studies have been made on the two highest parts of the Shickshocks—the broad plateaulike masses known as Mount Albert (summit altitude 3775 feet) and Tabletop Mountain (4230 feet). Glacial erratics possibly derived from pre-Cambrian rocks from north of the St. Lawrence were found as high as 3760 feet on Mount Albert. On Tabletop Mountain, striated surfaces were found as high as 3500 feet, and glacial erratics (of local origin) as high as 3700 to 3800 feet. Detailed search failed to produce any direct evidence of glaciation through the highest 400–500 feet. Throughout this distance evidences of any possible glaciated surfaces are obscured by mantles of locally derived felsenmeer that presumably originated in postglacial time. In addition, the composition of the bedrock is so heterogeneous that several types of erratic stones might be present without having been recognized. These circumstances do not demonstrate glaciation of the highest parts of Tabletop Mountain; yet there is no geologic evidence inconsistent with the possibility that the entire Shickshock highland was overtopped by Wisconsin ice. No geologic evidence was found, suggesting that any portion of the area existed as a nunatak during the Wisconsin maximum.
During the waning stages of glaciation, and possibly earlier, Tabletop was the site of radial outflow from a local ice cap.