About Seneca Lake

Fun Facts

Seneca Lake was carved out of bedrock over 10,000 years ago by glaciers, it is the deepest freshwater lake east of the Mississippi River outside of the Great Lakes. The lake’s shoreline is found within Seneca, Ontario, Yates and Schuyler Counties.


Seneca Lake

Interesting Facts:

  • 38 miles long
  • 3.2 miles at greatest width
  • 1.9 miles wide on average
  • 633 feet deep, at maximum
  • 66.3 square miles or about 42,400 acres
  • 4.2 Trillion gallons of water
  • 75 miles of shoreline
  • 11 municipalities rely on the lake for public water systems
  • 100,000 people rely on Seneca Lake as their primary water source


What Science Tells Us About Seneca Lake
featuring John Halfman 

John Halfman, Ph.D., teaches in the Department of Geoscience and Environmental Studies Program at Hobart and William Smith Colleges in Geneva, NY.