This region straddles the northern and transitional edge, known as the Finger Lakes Uplands and Gorges ecoregion, of the Northern Allegheny Plateau and the Ontario Lowlands ecoregion of the Great Lakes Lowlands.Cayuga and Seneca Lakes are among the deepest in the United States - 435 feet (133 m) and 618 feet (188 m) respectively - with bottoms well below sea level.
Glacial debris, possibly terminal moraine left behind by the receding ice, acted as dams, allowing lakes to form.
The Manchester Gateway Trail is a scenic route used by walkers and cyclers that follows the Canandaigua Outlet through Manchester.
It has also been used for skiing during winter months. The Ontario Pathways Rail Trail is the crown jewel of the trail system managed by the organization for whom it is named in Ontario County, New York.
It may have been formed in the same manner as the Finger Lakes, as satellite photos show three valleys similar in character and spacing to the Finger Lakes east of Otisco Lake.
The first is the Tully Valley, which includes a chain of small lakes at the south end that could be a "Finger Lake" that never formed because of a terminal moraine.