Tully is the largest of six glacial lakes (along with Crooked, Tracy, Mud, Green, and Song) clustered together–and collectively known as the Tully Lakes–in a wide valley bordered by rounded hills. The lakes sit on glacial debris call Valley Heads Moraine, which was deposited at the southern end of the Tully Valley. This moraine constitutes part of the St. Lawrence Seaway Divide that separates the north-flowing drainage into the Tully Valley and the south-flowing drainage of the Tioughnioga Valley.
The West Branch of the Tioughnioga River begins in a wet area just east of the Village of Tully and enters Tully Lake on the lake’s southeastern side and continues from the southern end of the lake.
For a more detailed explanation of the lakes’ physical features and some interesting maps, see “Hydrogeology of the Tully Lakes Area in Southern Onondaga and Northern Cortland Counties, New York” by the U.S. Geological Survey.
Formed in 1972, The Tully Lake Property Owners Association aims to support the owners who live year-round and seasonally on this magnificent Kettle Lake on the border of Onondaga and Cortland counties. This organization is not-for-profit and intends to help keep Tully Lake healthy, pristine and a premier recreation area. TLPOA participates in collaboration with organizations such as C-OFOKLA, The Cortland-Onondaga Federation of Kettle Lake Associations, Inc., and NYSFOLA the New York State Federation of Lake Associations, Inc.