Seneca Lake was formed by glaciers many years ago. It is just over 38 miles long and has a maximum depth of over 600 feet. It is the largest and deepest of the Finger Lakes. The lake has two main inlets. Catharine Creek and the Keuka Lake Outlet that provide most of the water entering the lake. The outlet for Seneca Lake is the Seneca River and is also known as "The Canal". The Seneca River joins Seneca and Cayuga lakes at their northern ends near the Montezuma Swap. The Seneca River also links to the N.Y. State Barge Canal system allowing boaters to travel across the state or from one lake to another.
Seneca Lake is home to the following species of fish lake trout, brown trout, rainbow trout, landlocked salmon, largemouth bass, smallmouth bass, yellow perch, northern pike, chain pickerel, rock bass, crappie, sunfish, bullheads, bowfin, white suckers, channel catfish, lake sturgeon, carp, alewives and smelt. The state does an annual stocking of lake trout, brown trout and landlocked salmon. The lake's rainbow trout population is sustained entirely by natural reproduction in Catherine Creek and its tributaries. So catch and release of rainbow trout in Seneca Lake is greatly encouraged.
Fishing Derbies on Seneca Lake include the National Lake Trout Derby which is held every Memorial Day weekend on Seneca Lake. New this year was the
Red Cross Fishing Derby which was a big hit with fisherman. Many fishing clubs have their own contest for bass, trout and perch here as well.