we like Tomkins Campground located at Cowanesque Lake. It is locate about 2 miles south of the New York/Pennsylvania state line off route 15. We have stayed there a couple of times. It is operated by the US Army Corps of Engineers and reservations can be made through the national reservation system. Many things to do. Nice sites, some with shade. Both times we were there during the summer, we did not need reservations. This is the website. http://www.recreation.gov/camping/tompkins/r/campgroundDetails.do?contractCode=NRSO&parkId=73446
Ray