Hiking in Maine: Outdoors adventures await at Lily Bay State Park Located in Greenville, the park offers swimming, paddling, hiking trails and 90 campground sites. By CAREY KISH Share The sand and gravel beach at Lily Bay State Park is a fun place on a summer day, with a great view to boot. Carey Kish photo The blinking yellow traffic light on Route 6/15 in the center of Greenville is the starting point of many great adventures in the Moosehead Lake region. Guidebooks, tourism brochures, shopkeepers, the visitor center and local folks all reference the spot when giving directions to area attractions, like Lily Bay State Park.