Hanging Bog State Preserve features a shaded hillside seep that houses a large population of skunk cabbage. It was formed from mineral-rich groundwater that flowed across bedrock, which created deposits of porous lime and formed terraces on the forested hillside. Skunk cabbage, which gets its name from its large leaves and skunky odor when damaged, thrives in these conditions. The plant, which often grows through a layer of snow as early as February, is accompanied by marsh marigold and jewelweed in the hillside seep. More than 170 plant species and 23 species of mosses and liverworts also grow on the preserve. Colorful spring wildflowers appear each year such as yellow anthers and maroon prairie trillium. Ferns are also numerous in the forest.

Leslie F. Clark deeded the area to the Iowa chapter of The Nature Conservancy in 1968 and it became a state preserve in 1981.

Fees, permits, and reservations may apply.