The Baldface Hill Gneiss of the Oswegatchie Group, here named, is at Baldface Hill in the Northwest Lowlands of the Adirondack Mountains, New York. Consists of layered, rusty-brown-weathering biotite-garnet-sillimanite gneiss. Although outcrops are discontinuous, the unit may be continuous but not well exposed. Unconformably overlies the Alexandria Bay Gneiss (new name) of the Piseco Group (new name); underlies the Poplar Hill Gneiss (new name) and Gouverneur Marble of the Oswegatchie Group in the Northwest Lowlands. Correlates with the Eagle Lake Gneiss of the Lake George Group (both new names) in the eastern Adirondacks. Thickness ranges from 30 to 300 m. Age is Proterozoic.
Type locality: exposures along the rocky face of Baldface Hill, 3 to 5 km north of Harrisville, Harrisville 7.5-min quadrangle, Lewis Co., NY.

Source: US geologic names lexicon (USGS Bull. 1565, p. 18-19).