It is the southernmost boreal bog east of the Mississippi River, containing many black spruce and tamarack trees at the southern limit of their ranges.

Like many bogs, its terrain presents an image of solidity, but a liquid mass of decaying peat lies beneath a six-inch (152 mm) layer of sphagnum and a network of supporting tree roots.

The bog began as a "kettle lake" formed approximately 10,000 years ago by a portion of the retreating Wisconsin Glacier (named according to geologic epoch, not location), which initially covered a depth up to the top of the current forest canopy.

With restricted air and nutrient flow, sphagnum moss grew out into the lake, eventually forming a layer of peat over 40 feet (12 m) thick.

The area held by this organization has increased by gifts and purchases to over 1,000 acres (4.0 km2), and adjoins on additional public lands.