The Grove is the eastern extremity of a line of high ground known to Rochesterians as the Pinnacle Range, which extends from here roughly in a westward direction to the Genesee river. The Pinnacle Range is part of a larger moraine deposited approximately 11,000 to 12,000 years ago by the receding ice front of an enormous glacier. Within the Grove the action of the glacier is especially evident in the two steep-sided depressions (kettles) formed by slowly melting ice chunks trapped within the deposited material. As a result of the formation of the terrain, the soil in the Grove is predominantly sand and gravel for a considerable depth. Its high permeability affects plant species composition and distribution.