The Espy Bog (also known as the Espy Wetlands) is wetland complex in Columbia County, Pennsylvania, in the United States. It is situated near Bloomsburg and Espy. The wetlands contain a lake, as well as forested swamps, shrub swamps, and graminoid openings. The lake in the wetland complex may be manmade. The predominant soil in the area is known as mucky peat. The wetland complex has a high level of plant and animal biodiversity, including birds, turtles, fish, trees, shrubs, and ferns.