Kettle ponds formed about twelve thousand years ago at the end of the last Ice Age when the Laurentide Glacier began to retreat. As massive blocks of ice broke off and were buried in glacial outwash, they melted and collapsed the ground, leaving deep circular basins that filled with groundwater. When these depressions first formed, the land was tundra. Mastodons, woolly mammoths, and giant beavers moved across open plains of sedge and spruce. Over time, forests replaced the tundra and the kettle