Devil's Lake State Park is a state park located in the Baraboo Range in eastern Sauk County, Wisconsin, United States. It is just south of the city of Baraboo, around 35 mi (56 km) northwest of Madison, and is on the western edge of the last ice-sheet deposited during the Wisconsin glaciation. The state park encompasses 9,217 acres (3,730 ha), making it the largest in Wisconsin. The state park is known for its 500-foot-high (150 m) quartzite bluffs along the 360-acre (150 ha) Devil's Lake, which was created by a glacier depositing terminal moraines that plugged the north and south ends of the gap in the bluffs during the last ice age approximately 12,000 years ago. The sand at the bottom of Devil's Lake is thought to be deposited by glaciers.