We do an annual hiking trip at Ross Lake.  Amazing hikes, glacier-fed lake - which is icy cold if you decide to hike all the way up to Desolation Outlook and need to cool down your body after the evaluation climb.  You can rent motorized boats to access even more campgrounds.  Canoe or stand up paddleboard.  There are always rangers refilling toilet paper and checking on the conditions of the pit toilets which I always appreciate and bear boxes to keep your food safe.