Boulder Reservoir is a large recreational area located in Boulder, Colorado. It covers approximately 700 acres and features a 100-acre lake, making it a popular destination for various outdoor activities. Visitors can enjoy swimming, sailing, paddleboarding, and fishing, as well as picnicking along the shoreline. The reservoir is surrounded by scenic views of the Flatirons and offers amenities such as picnic areas, restrooms, and a designated swimming beach. It also has trails for walking and biking, making it a great spot for families and outdoor enthusiasts to relax and enjoy nature.