Bogs are composed of saturated peat soils that are low in nutrients and very acidic. Bogs originate in a shallow lake as a floating mat of sedges that becomes colonized by sphagnum moss. As the mat gradually thickens and stabilizes, it is invaded by shrubs and trees. Over time, the bog mat expands until no open water is visible. This transformation from open water to forest is very slow and can take thousands of years.

The peat is typically covered by a low-growing carpet of sphagnum moss. Low nighttime temperatures in bogs (often 30 degrees cooler than the surrounding uplands) are ideal for sphagnum moss, which acts as an insulator for the roots of other plants. Plants typically found in bogs include sedges and shrubs such as bog rosemary, Labrador tea, bog laurel, lowbush blueberry, and leatherleaf.

Carnivorous plants like pitcher plants and sundew are common in bogs. Bogs are also home to turtles, frogs, salamanders, and snakes. The spotted turtle and the red-bellied snake are two of the rarer finds in a bog, and they are protected by the State of Michigan.