Castle Rock Lake before 1951 was an ancient, unnamed glacial lake bed that held farmlands, vast prairies, and forested knolls separated by the Wisconsin River. Castle Rock Lake is the fourth largest lake in Wisconsin, it covers sixteen thousand acres, and has approximately seventy miles of shoreline. Castle Rock Lake is home to a large variety of fish, birds, and many other organisms. The large body of water attracts many people to the area as well, it provides a great space for recreational hobbies such as bird watching, boating, fishing, and recreational water sports.