President Obama and his family are scheduled to vacation on Mount Desert Island next weekend, Rep. Chellie Pingree's office said Friday. Obama, his wife, Michelle, and daughters Sasha and Malia are expected to visit Acadia National Park, which is on the island, during their visit from July 16-18. The 47,000-acre park averages more than 2 million visitors annually and is the only national park in New England. Mount Desert Island is about 108 square miles and a short distance off the Maine coast. It has long been a summer vacation haven for some of America's wealthiest and most prestigious families....