Both the Birch Creek and Nails Creek units of Lake Somerville State Park offer a multitude of recreational opportunities such as camping, picnicking, boating, fishing, hiking and biking, volleyball, horseshoes, basketball, backpacking and equestrian use (visitors must bring their own horses). More than 20 miles of trail are open to hikers, mountain bikers and equestrians, affording visitors the opportunity to exercise and enjoy the beauty of the park. Water lovers can enjoy boating, fishing, swimming and skiing on Lake Somerville.
The Lake Somerville Trailway, located around the west end of the reservoir, connects Birch Creek State Park with Nails Creek State Park via 13 miles of trails for hiking, mountain biking, horseback riding, backpacking, birding, and nature study. Flag Pond, located approximately 4 miles from Nails Creek State Park and 9 miles from Birch Creek State Park along the Somerville Trailway, provides waterfowl hunting and non-consumptive wildlife viewing opportunities in conjunction with a system of interpretive trails, nature study, outdoor classrooms, and wildlife photography. The Flag Pond Nature Theater provides an excellent wildlife-viewing platform.