A kettle at the Middle

A kettle lake is a natural lake formed when a glacier retreats, and a large block of ice is left stranded. This is then covered in the rock and gravel shoved out by the glacier. As the ice melts, a depression forms, gradually filling with water. This kettle lake in the photo is locally known as "Middle lake". I found it quite interesting as I was unsure how the water hasn't totally vanished, given that there's no streams into the lake, and the water evaporates and sinks underground. Eventually the water will vanish, forming a marsh and then being taken over by forest.