Is Copake Lake spring-fed? It depends on who you ask.

To the average person, a spring-fed lake is one without obvious rivers or streams feeding it. Copake Lake fits this description, as it has a small watershed with few streams.

However, scientists and engineers define a spring-fed lake as one where most water comes from the ground. Data shows Copake Lake actually loses more water to the ground than it gains. Its level constantly drops unless replenished by rain or snowmelt, making it a precipitation-fed lake in scientific terms.

The warm "springs" felt while swimming are not groundwater springs, but convection currents caused by solar heating. Copake Lake does have a few cold groundwater springs, but they're insignificant compared to its water loss.

So, while Copake Lake may appear spring-fed to the casual observer, it doesn't fit the scientific definition. The lake's primary water source is precipitation, and its level is constantly fluctuating due to evaporation and groundwater loss.